Effects of selenium application on reducing cadmium uptake and ameliorates cadmium stress on oilseed rape (Brassica napus L.) in cadmium-contaminated soil

Effects of selenium application on reducing cadmium uptake and ameliorates cadmium stress on oilseed rape (Brassica napus L.) in cadmium-contaminated soil | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Effects of selenium application on reducing cadmium uptake and ameliorates cadmium stress on oilseed rape (Brassica napus L.) in cadmium-contaminated soil Cixing He, Yuanyuan Zhao, Tingqiang Li, Chengxiao Hu, Zhen Wang, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4976345/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Cadmium is considered a highly toxic metallic element that does not have any beneficial biological functions for humans or plants. It has been reported that the antagonism of selenium to heavy metal stress has been observed in a variety of plants, and appropriate selenium could alleviate heavy metal-induced oxidative damage and reduce the accumulation of heavy metals in plants. The changes of physiological characteristics, root tip cells, cadmium concentration and accumulation of rape under cadmium stress were investigated in this study through pot experiment. Results showed that selenium could alleviate the inhibitory effect of cadmium on the growth of rape seedlings. The concentration and accumulation of cadmium were decreased after the selenium application in rape seeds, ranging from 19.93 to 22.97% and 27.96 to 43.88% respectively. And the decrease of photosynthetic pigment content induced by cadmium was significantly improved. The results of transmission electron microscopy showed that exogenous selenium and cadmium had metal complexation reaction and formed black precipitation, which may be related to the detoxification effect of selenium on cadmium. More critically, with the addition of selenium, the plasma membrane damage and free radical accumulation in root tips induced by cadmium stress were gradually alleviated in the histochemical staining experiment of rape root tips. These results may provide evidence for exploring effective measures to reduce cadmium accumulation in rape under cadmium-contaminated areas. Cadmium Selenium Brassica napus L. Photosynthetic pigment Root tips Reactive oxygen species Figures Figure 1 Figure 2 Figure 3 1. Introduction Cadmium (Cd) is one of the most toxic heavy metals widely present in the environment around the world [ 1 ]. Under natural conditions, Cd is produced mainly through volcanic emissions and rock weathering. At the same time, anthropogenic activities such as mineral mining, waste emissions, garbage incineration and the use of chemical fertilizers can increase the level of Cd contamination in soil, water and air, thereby increasing the level of Cd contamination in the food chain [ 2 ]. Over the past three decades, Chinese rapid industrialization has caused serious concern about the extent of soil pollution, among which Cd pollution has become one of the major environmental issues threatening China’s food security and sustainable agricultural development [ 3 ]. In addition, Cd pollution also threatens the health of animals, plants and humans, and has attracted global attention [ 4 – 6 ]. At present, considerable efforts have been made to reduce the accumulation of Cd in crops and soil, including reducing the availability of Cd in the soil, using phytoremediation or soil washing to remove Cd from the soil, and cultivating Cd through breeding or genetic engineering [ 7 , 8 ]. Varieties with low accumulation, applying soil amendments, regulating water management, and spraying foliar fertilizers [ 9 – 12 ]. However, the limitation of these measures was that they are inconvenient to apply, consume a lot of manpower, material resources and time, cause soil ion imbalance, and some may even damage crop growth and fail to increase crop yields [ 13 , 14 ]. Although transgenic approaches could reduce Cd accumulation in crops [ 12 , 15 ], concerns about transgenic crops make them less acceptable to the public. Therefore, urgent action is needed for limit the accumulation of Cd in plants and reduce its toxicity. Selenium (Se) is a mineral nutrient element that has been shown to promote plant growth under adverse conditions and increase tolerance to environmental stresses [ 16 ]. Studies have shown that Se application could significantly reduce the accumulation of Cd, As and Pb in wheat grains in field experiment [ 17 ]. Exogenous Se improves the adverse effects of heavy metals on plants by inhibiting the absorption of heavy metals and improving the antioxidant system [ 18 , 19 ]. In addition, Se could also restore the photosynthetic function of plants under heavy metal stress, to promote plant growth [ 18 ]. The effects of Se on plant Cd toxicity have attracted widespread attention from researchers. A large number of studies have reported Se-mediated reduction of Cd accumulation in crops. For example, it was observed in cucumbers that 6 mmol/L selenite treatment reduced the Cd content in cucumber leaves, stems, and roots by 43%, 26%, and 23% [ 20 ]. Spraying Se in rice reduced the Cd content in grains, stems and roots by 61.6%, 51.0% and 26.9% respectively [ 21 ]. This is related to Se inhibiting the absorption of Cd by plants and reducing the transport of Cd from roots to shoots [ 22 , 23 ]. In addition, Se can also affect the accumulation of Cd in plants by changing the subcellular distribution of Cd [ 24 ]. In rice suspension cells, it was found that Se reduced the Cd content in the cells by regulating the expression of Cd-related genes ( OsLCT1 , OsNramp5 , OsNramp1 , OsIRT1 and OsIRT2 ), and a large amount of Cd accumulated in the cell wall and reduced the diffusion into the cells [ 25 ]. Moreover, Se tends to counteract Cd-induced changes in nutrient element content in plants [ 26 ], which may be one of the important mechanisms by which Se alleviates Cd stress. However, there are also some controversial reports on the synergistic effect between Se and Cd. Researchers have found that spraying selenite on tobacco enhanced Cd accumulation in tobacco leaves [ 27 ]. When the Cd level is low, Se application reduces the Cd content in the above-ground parts of pakchoi, while Se application increases the Cd content under high Cd levels []. Given that the specific regulatory effect of Se on Cd toxicity is affected by a variety of conditions, including the doses of the two elements [ 28 ], the type of Se [ 29 ] and the plant species [ 30 ], etc., the details of these influencing processes still require further study. Exogenous Se could alleviate oxidative stress induced by heavy metals in plants [ 31 ]. Although this helps to better understand the mode of action of Se in regulating heavy metal accumulation in plants, Se enhances plant resistance to heavy metal stress. The specific mechanisms of resistance are not yet fully understood. Supplying an appropriate amount of Se to plants can effectively reduce the absorption and accumulation of Cd by plants. Since there is a dose-dependent relationship between Cd and Se, in practical applications, it is necessary to consider how the doses of the two elements will directly affect the regulation of Se and Cd toxic effects, the underlying mechanisms of which are unknown. The ability of plants to tolerate and accumulate heavy metals is also closely related to plant species. Brassicaceae crops have a strong ability to accumulate Se and Cd. We have explained the response of Se application to Cd-sensitive rapes under Cd stress in our previous study. However, the effects and underlying mechanisms of Se application on Cd-tolerance rapes varieties are still unclear. Therefore, this study selected Cd-tolerance of Brassica napus L. as the research object, focusing on the interaction between Se, Cd and roots, aiming to explore the potential role of exogenous Se in regulating Cd absorption and distribution in rape plants. With this study, we aimed to: (1) investigate the effects of exogenous Se application on the growth and photosynthetic parameters of rape under Cd stress; (2) explore whether Se could restore the structure of rape root tip cells under Cd stress; (3) explore the effects of Se on Cd content and translocation factor in rape plants under Cd stress. 2. Materials and methods 2.1 Experiment site and soil characterization Experiments were carried out in the Micro-Element Research Center at Huazhong Agricultural University (30º28′26′′N, 114º2′15′′E), Wuhan, China. The soil was collected from the upper layer (0–20 cm) of a test field in Huazhong Agricultural University. The characteristics of the tested soil were as follows: pH 5.07, organic matter 23.81 mg kg − 1 , available N 110.40 g kg − 1 , available P 296.40 mg kg − 1 , available K 437.67 mg kg − 1 , total Cd 0.24 mg kg − 1 , and total Se 0.16 mg kg − 1 . 2.2 Experimental design Two levels of Cd (0.5 and 5 mg kg − 1 ) and four levels of Se (0, 0.1, 1 and 5 mg kg − 1 ) were arranged in a randomized block design. Cd chloride (CdCl 2 ·2.5H 2 O) and sodium Se (Na 2 SeO 3 ) of analytical grade were added and mixed thoroughly with soil (5.5 kg), and then placed in plastic pots 22 cm in diameter and 35 cm in height. In order to meet the nutritional needs of the whole growth period, the soil was fertilized with the following macronutrients (g kg − 1 soil): nitrogen (N) 0.2, phosphorus pentoxide (P 2 O 5 ) 0.15 and potassium oxide (K 2 O) 0.2 supplied in the form of cobalt amide [CO(NH 2 ) 2 ], ammonium phosphate monobasic (NH 4 H 2 PO 4 ) and potassium sulphate (K 2 SO 4 ) respectively. Besides, the application of microelements (g kg − 1 soil) was 0.025 mg iron ethylenediaminetetraacetic acid (Fe-EDTA), 1.81 mg manganese (II) chloride tetrahydrate (MnCl 2 ·4H 2 O), 0.08 mg copper (II) sulfate pentahydrate (CuSO 4 ·5H 2 O), 0.22 mg zinc sulfate heptahydrate (ZnSO 4 ·7H 2 O) and 2.86 mg boric acid (H 3 BO 3 ). All the fertilizers used were analytical grade, and deionized water was used during the period. Rape ( Brassica napus L.) cultivar ‘Zhongshuang 9’ was used in this study. This species has strong resistance to Cd were based on the preliminary experiments performed by our group [ 32 – 34 ]. Eight treatments were established with four repetitions. Seeds were sowed directly in soil. After two weeks, two healthy and uniform seedlings were selected and left to grow up in each pot. The containers and plants were put under a rainproof shelter. Two whole rape plants were collected from each pot in the mature period. After rinsing with deionized water three times, plants were divided into four parts (root, shoot, pod and seed). One part of the samples were oven dried to a constant weight, weighed and ground into powder before determination. The other part of the sample were stored in the − 80 ℃ refrigerator for analysis of physiological indicators. 2.3 Total Cd and Se determination Plant samples were digested with 10 mL mixture acid (HNO 3 : HClO 4 9:1, v/v) at an electric plate. After heating up to a clear solution about 1 mL, the solution was diluted to 50 mL by deionized water. The supernatant was subjected to a flame atomic absorption spectrometry (Z-2000, HITACHI, Japan) to detect the total Cd concentration [ 35 ]. For measuring total Se concentration, samples were digested with 10 mL mixture acid (HNO 3 : HClO 4 9:1, v/v). After heating to almost 1 mL solution left in the flask, 10 mL HCl (1:1, v/v) was added and heated until white smoke appeared. The acid digests were diluted to 50 mL with deionized water. Se concentration in the supernatant was measured by an atomic absorption spectrometer equipped with a hydride generation system (AFS-8220, Beijing Jitian Instruments Co., China) according to the previous method [ 36 ]. The quality assurance of Cd and Se analysis process was checked by a reference material of plant GBW10015 (GSB-6) purchased from the National Center of Standard Material in China. 2.4 Determination of photosynthetic pigment content Wash and dry the fresh rapeseed leaves. Cut the leaves into small pieces with scissors while avoiding the veins. Weigh about 0.20 g of the fragments and put them into a 25 mL colorimetric tube. Add 25 mL of 95% ethanol and soak the rapeseed in a dark place. The leaf color turns completely white. Using 95% ethanol as a blank control, use the multi-wavelength scanning function of a spectrophotometer (UV-5200) to measure the absorbance value of the soaking solution at 665, 649 and 470 nm. Calculate the contents of chlorophyll a, chlorophyll b and carotenoids, the calculation formula is as follows: C chlorophyll a =13.95×A 665 -6.88×A 649 , C chlorophyll b =24.96×A 649 -7.32×A 665 , C carotenoids = (1000×A 470 -2.05× C chlorophyll a -114.8× C chlorophyll b )/245. 2.5 Preparation and observation of root transmission electron microscopy sections Take the roots of fresh rapeseed samples, wash them with deionized water, and then use a stainless steel blade to cut about 20 root tips about 1–3 mm long. Immediately place the cut root tip into a fixative (2.5% (v/v) glutaraldehyde in 50 mmol/L sodium phosphate buffer (PBS, pH 6.8)). When preparing samples, the root tips were first washed three times with the same sodium phosphate buffer, and then allowed to stand in 2% osmium tetroxid fixative solution (osmium tetroxid) prepared with 50 mmol/L sodium cacodylate (pH 7.2) for 2 h, and then washed 3 times with sodium phosphate buffer. Subsequently, the samples were dehydrated in 30%, 50%, 70%, 80%, 90%, and 100% ethanol (v/v) for 15 min. The root tip samples were embedded in Epon 812 resin overnight, and then the samples were cut into ultrathin sections of about 80 nm using an ultrathin cryostat (UC6, LEICA, Germany) and placed on a copper grid. The samples were fixed, dehydrated, cut and observed by transmission electron microscope (H-7650, HITACHI, Japan) on the electron microscope platform of Huazhong Agricultural University. 2.6 Plasma membrane integrity histochemical staining Soak the sample roots in 0.5 mmol/L CaCl 2 (pH 4.5) solution for 5 minutes, then wash and blot dry. Then, the roots were soaked in 4 mL of 0.025% (w/v) Evans blue solution (dissolved in 100 µmol/L CaCl 2 , pH 5.6) for 30 min, and the roots were fully rinsed with sufficient distilled water until no blue color was visible in the water. Cut the root tip and place it on a glass slide. Add a small amount of water and cover it with a coverslip to observe it under an optical microscope. 2.7 Statistical analysis of data The translocation factor (TF) and bioconcentration factor of Cd from root to aboveground parts were estimated as follows: TF root−stem = Cd stem /Cd root TF stem−pod = Cd pod /Cd stem TF stem−seed = Cd seed /Cd stem BCF = Cd plant samples /Cd soil Cd root , Cd stem, Cd pod , and Cd seed are the concentrations (mg kg − 1 , dry weight) of Cd in the roots, stems, pods, and seeds of rape plants, respectively. SPSS 26.0 software was used for statistical analysis of all data. The results were analyzed by two-way ANOVA. The mean values of every treatment were conducted a multiple comparisons by the Duncan test ( P < 0.05). The results are the means ± SE (standard error) of four replicates. All tables and figures were performed by Excel 2013 and Sigma Plot 12.5. 3. Results 3.1 Effects of Se on plant growth In the mature period, the whole rape plant was divided into four parts, including root, stem, pod and seed. After 20 days of treatment, the effect of each treatment on the growth of rape seedlings was shown in the Table 1 . The results showed that the dry weight of the shoots and roots was significantly increased in the high Cd level (5 mg kg − 1 ), which may be toxic effect of Cd on plants. It is worth noting that, with Se levels increased in the soil, the dry weight of shoots and roots was significantly increased under same Cd level. At the low Cd level (0.5 mg kg − 1 ), compared with Cd0.5 treatment, Cd0.5Se0.1, Cd0.5Se1 and Cd0.5Se5 increased the biomass of root by 4.71%, 17.85% and 10.27%. At the same time, the pod and seed increased by 5.56%-6.92% and 4.97%-5.48% with the application of Se. At the high Cd level (5 mg kg − 1 ), compared with Cd5 treatment, Cd5Se0.1, Cd5Se1 and Cd5Se5 make the biomass of root, pod and seed decreased firstly and increased subsequently. Table 1 Dry weight variation in different parts of rapes grown in soil with different concentrations of Se and Cd. Treatment Dry Biomass (g/plant) Root Stem Pod Seed Cd0.5 4.21 ± 0.17 cd 9.79 ± 0.59 a 7.91 ± 0.29 c 9.55 ± 0.28 c Cd0.5Se0.1 4.41 ± 0.23 bc 9.37 ± 0.12 a 8.46 ± 0.44 bc 10.07 ± 0.95 bc Cd0.5Se1 4.96 ± 0.13 ab 9.29 ± 0.55 a 8.35 ± 0.20 bc 10.07 ± 0.20 bc Cd0.5Se5 4.64 ± 0.13 abc 9.63 ± 0.23 a 8.45 ± 0.24 bc 10.02 ± 0.27 bc Cd5 5.08 ± 0.12 a 10.18 ± 0.39 a 9.82 ± 0.22 a 12.50 ± 0.21 a Cd5Se0.1 3.64 ± 0.17 d 9.36 ± 0.29 a 7.41 ± 0.19 c 8.72 ± 0.44 c Cd5Se1 4.45 ± 0.36 abc 9.56 ± 0.62 a 7.87 ± 0.56 c 9.52 ± 0.42 c Cd5Se5 4.92 ± 0.21 ab 9.93 ± 0.36 a 9.35 ± 0.48 ab 11.25 ± 0.68 ab The mean values (± SE) in each column followed by different letters indicated significant difference among different treatments according to two-way ANOVA followed by Duncan multiple comparison ( P < 0.05). In addition, Cd-induced changes in the photosynthetic pigment content of rape seedlings were partially diminished by Se, especially under higher Cd levels (Table 2 ). Under the two Cd levels, the chlorophyll a, chlorophyll b, carotenoid content and total chlorophyll showed an increasing trend with the increase of Se concentration in the soil. In the Cd0.5 treatment, Cd0.5Se1 and Cd0.5Se5 significantly increased the chlorophyll a, chlorophyll b and total chlorophyll content. Compared with Cd0.5, Cd0.5Se0.1, Cd0.5Se1 and Cd0.5Se5 increased the chlorophyll a content by 11.34%, 31.60% and 48.11%, the chlorophyll b content increased by 12.57%, 33.33% and 54.17%, the carotenoid content increased by 6.25%, 25.01% and 37.55%, and the total chlorophyll content increased by 11.62%, 32.00% and 49.51% respectively. In the Cd5 treatment, Cd5Se1 and Cd5Se5 significantly increased chlorophyll a, chlorophyll b, carotenoid content and total chlorophyll content. Compared with Cd5, Cd5Se1 and Cd5Se5 increased the chlorophyll a content by 43.71% and 40.68%, the chlorophyll b content increased by 47.31% and 47.31%, the carotenoid content increased by 35.77% and 35.77%, and the total chlorophyll content increased by 44.52% and 42.18%. These results showed that Se can significantly increase the photosynthetic pigment content of rape leaves under Cd stress. Table 2 Effects of Se on leaf photosynthetic pigment content of rapes under Cd stress. Treatment Chlorophyll a (mg/g FW) Chlorophyll b (mg/g FW) Carotenoids (mg/g FW) Chlorophyll a + b (mg/g FW) Cd0 1.26 ± 0.06 a 0.39 ± 0.02 a 0.25 ± 0.01 a 1.65 ± 0.07 a Cd0.5 0.79 ± 0.05 cde 0.24 ± 0.02 cd 0.16 ± 0.01 bc 1.03 ± 0.06 cd Cd0.5Se0.1 0.88 ± 0.04 cd 0.27 ± 0.01 bc 0.17 ± 0.01 bc 0.15 ± 0.05 f Cd0.5Se1 1.04 ± 0.06 bc 0.32 ± 0.02 ab 0.21 ± 0.02 ab 1.36 ± 0.08 b Cd0.5Se5 1.17 ± 0.09 ab 0.37 ± 0.03 a 0.22 ± 0.01 ab 1.54 ± 0.12 ab Cd5 0.64 ± 0.01 de 0.19 ± 0.00 de 0.14 ± 0.01 bcd 0.83 ± 0.02 e Cd5Se0.1 0.58 ± 0.03 e 0.17 ± 0.02 de 0.12 ± 0.00 cd 0.78 ± 0.04 e Cd5Se1 0.92 ± 0.04 bc 0.28 ± 0.02 bc 0.19 ± 0.01 abc 1.20 ± 0.06 bc Cd5Se5 0.90 ± 0.06 bc 0.28 ± 0.02 bc 0.19 ± 0.01 abc 1.18 ± 0.08 bc Statistical significance Cd p < 0.01 p < 0.01 p < 0.01 p < 0.01 Se p < 0.01 p < 0.01 p < 0.01 p < 0.01 Cd \(\:\times\:\) Se p < 0.01 p < 0.01 p < 0.01 p < 0.01 Data are the means of four replicates. The mean values (± SE) in each column followed by different letters indicated significance among different treatments according to two-way ANOVA followed by Duncan multiple comparison ( P < 0.05). 3.2 Effects of Se on root tip cell in rape under Cd stress Compared with root tip cells treated with low Cd, the mitochondria of root tip cells treated with high Cd were more swollen, the ridges inside the mitochondria were relatively disordered, and the cell wall shape was irregular. Intuitively, Se did not restore the morphological damage of mitochondria and cell walls induced by Cd, which may be related to the Se and Cd concentrations and treatment time in this experiment. Moreover, some black precipitates were observed in Cd5Se5 treatment rapeseed root cells, which were presumed to be metal precipitate complexes (Fig. 1 ). Next, we further explored the effect of Se on the root tip plasma membrane integrity of rapeseed under Cd stress (Fig. 2 ). The color depth and distribution of Evans blue reflect the degree of root tip plasma membrane damage. With the Cd concentration increased, the absorption of Evans blue in the root tips increased and showed a darker blue color. Compared with roots treated with Cd alone, the blue color of the root tips treated with Se and Cd was reduced to varying degrees, indicating that Se reduced the plasma membrane damage induced by Cd in roots. Subsequently, we used histochemical staining to study the effect of Se on the accumulation of superoxide ions in rapeseed under Cd stress. NBT reacts with superoxide anions (O 2 − ) to form a dark blue insoluble formazan compound, which can reflect the degree of accumulation of superoxide ions. With Cd concentration increased, the root tips took on a darker blue color, indicating increased superoxide ion accumulation. Compared with roots treated with Cd alone, the color of the root tips treated with Se and Cd was reduced to varying degrees. These results indicated that Se plays an important role in scavenging Cd-induced reactive oxygen species (ROS) in roots. 3.3 Effects of Se on Cd concentration and accumulation in different parts of rapes under Cd stress After exogenous Se was added to Cd-contaminated soil, the Cd concentration and accumulation of rapeseed roots, stems, pods and seeds changed to a certain extent (Tables 3 and 4 ). Under the 0.5 mg kg − 1 Cd level, with the Se level increases, the Cd concentration in roots and stems first decreases and then increases, the Cd concentration in pods were increased, and the Cd concentration in seeds first increases and then decreases. Compared with the Cd0.5, the Cd concentration in the roots decreased by 10.22% and 40.25% in the Cd0.5Se0.1 and Cd0.5Se1, and increased by 47.99% in the Cd0.5Se5. The stem Cd concentration decreased by 2.07% in the Cd0.5Se0.1 and increased by 4.13% in the Cd0.5Se1. The Cd concentration of the pod increased by 43.18%, 59.94% and 63.07% respectively in the Cd0.5Se0.1, Cd0.5Se1, and Cd0.5Se5. The Cd concentration significantly increased in the Cd0.5Se1 and Cd0.5Se5. The Cd concentration of seed increased by 10% in the Cd0.5Se0.1, and increased significantly in the Cd0.5Se0.1. The Cd0.5Se1 and Cd0.5Se5 decreased the Cd concentration by 20%. For Cd accumulation, with the soil Se level increased, the Cd accumulation in the roots first decreases and then increases, and the Cd accumulation in the pod increases. Compared with Cd0.5, the Cd0.5Se0.1, Cd0.5Se1, and Cd0.5Se5 decreased the Cd accumulation in stems by 6.38%, 1.56%, and 1.56%; the Cd accumulation in pods increased by 55.65%, 70.03% and 77.21%. The Cd accumulation in roots decreased by 4.59% and 30.86% in the Cd0.5Se0.1 and Cd0.5Se1, while it increased by 61.43% in the Cd0.5Se5. The Cd accumulation in seeds increased by 14.74% in the Cd0.5Se0.1, while it decreased by 10.53% and 11.58% in the Cd0.5Se1 and Cd0.5Se5, respectively. Table 3 Cd concentration in different parts of rapes grown in soil with different concentrations of Se and Cd. Treatment Cd concentration (mg/kg DW) Root Stem Pod Seed Cd0.5 3.23 ± 0.32 c 2.42 ± 0.25 c 3.52 ± 0.21 d 0.10 ± 0.02 c Cd0.5Se0.1 2.90 ± 0.62 c 2.37 ± 0.20 c 5.04 ± 0.38 cd 0.11 ± 0.02 c Cd0.5Se1 1.93 ± 0.22 c 2.52 ± 0.14 c 5.63 ± 0.41 c 0.08 ± 0.00 c Cd0.5Se5 4.78 ± 0.12 c 2.42 ± 0.09 c 5.74 ± 0.78 c 0.08 ± 0.00 c Cd5 18.13 ± 1.38 b 34.51 ± 1.81 ab 20.49 ± 0.63 a 2.96 ± 0.24 a Cd5Se0.1 29.92 ± 1.19 a 33.17 ± 1.00 b 17.88 ± 0.90 b 2.37 ± 0.31 b Cd5Se1 27.08 ± 2.76 a 36.14 ± 0.31 a 18.55 ± 0.35 b 2.28 ± 0.12 b Cd5Se5 19.72 ± 2.28 b 32.89 ± 0.80 b 19.04 ± 0.34 ab 2.37 ± 0.12 b The mean values (± SE) in each column followed by different letters indicated significant difference among different treatments according to two-way ANOVA followed by Duncan multiple comparison ( P < 0.05). Table 4 Cd accumulation in different parts of rapes grown in soil with different concentrations of Se and Cd. Treatment Cd accumulation (µg/plant) Root Stem Pod Seed Cd0.5 13.74 ± 1.82 c 23.66 ± 3.04 c 27.69 ± 1.00 d 0.95 ± 0.15 d Cd0.5Se0.1 13.11 ± 3.46 c 22.15 ± 1.66 c 43.10 ± 5.33 d 1.09 ± 0.10 d Cd0.5Se1 9.50 ± 0.86 c 23.29 ± 1.18 c 47.08 ± 3.82 d 0.85 ± 0.02 d Cd0.5Se5 22.18 ± 0.76 c 23.29 ± 1.04 c 49.07 ± 7.98 d 0.84 ± 0.02 d Cd5 92.19 ± 7.86 b 350.28 ± 17.89 a 201.20 ± 7.92 a 36.94 ± 3.08 a Cd5Se0.1 109.17 ± 7.90 ab 310.78 ± 17.55 b 132.29 ± 7.04 c 20.73 ± 3.21 c Cd5Se1 120.85 ± 17.56 a 345.77 ± 23.96 ab 146.35 ± 12.62 c 21.77 ± 1.72 c Cd5Se5 95.91 ± 7.71 b 325.73 ± 5.18 ab 177.87 ± 8.78 b 26.61 ± 1.74 b The mean values (± SE) in each column followed by different letters indicated significant difference among different treatments according to two-way ANOVA followed by Duncan multiple comparison ( P < 0.05). Under the 5 mg kg − 1 Cd level, with the level of Se increased in soil, the Cd concentration in the roots showed an increasing trend, while the Cd concentration in the pods and seeds showed decreasing trend. The Cd5Se0.1 and Cd5Se1 significantly increased the Cd concentration in roots. Compared with Cd5, the Cd5Se0.1, Cd5Se1 and Cd5Se5 increased the Cd concentration by 65.03%, 49.37% and 8.77% respectively. The Cd concentration was significantly decreased in the Cd5Se0.1 and Cd5Se1 in the pods. The Cd concentration was decreased by 12.74%, 9.47% and 7.07% in the Cd5Se0.1, Cd5Se1 and Cd5Se5. The Cd concentration of the seeds was significantly decreased by 19.93%, 22.97% and 19.93% in the Cd5Se0.1, Cd5Se1 and Cd5Se5. The Cd concentration of stems decreased by 3.88% in the Cd5Se0.1, increased by 4.27% in the Cd5Se1, and decreased by 4.69% in the Cd5Se5. For Cd accumulation, under the 5 mg kg − 1 Cd level, with the soil Se level increased, the Cd accumulation in the roots showed a trend of first increasing and then decreasing, while the Cd accumulation in the stems, pods and seeds were decreased to varying degrees. Compared with Cd5, Cd5Se1 significantly increased the Cd accumulation in roots. In the Cd5Se0.1, Cd5Se1, and Cd5Se5, root Cd accumulation increased by 18.42%, 31.09%, and 4.04%. The Cd5Se0.1 and Cd5Se5 significantly decreased the Cd accumulation in stems by 11.25% and 7.01%. Cd accumulation in pods was significantly decreased by 34.25%, 27.26% and 11.60%. Cd accumulation in seeds was significantly decreased by 43.88%, 41.07% and 27.96%. Taken together, the addition of exogenous Se to soil decreased the Cd concentration in various parts of rape, and significantly decreased the Cd concentration in seeds of rape. 3.4 Effects of Se on Se concentration and accumulation in different parts of rapes under Cd stress Adding exogenous Se to soil could significantly increase the Se concentration and accumulation in various parts of rape under Cd stress (Tables 5 and 6 ). In the low-Se treatments (Se0.1), the Se concentration of roots, stems, pods, and seeds of rape grown in 5 mg kg − 1 Cd-contaminated soil was similar to the Se concentration of various parts in the 0.5 mg kg − 1 Cd-contaminated soil. In the high-Se treatments (Se1 and Se5), the Se concentration of rape roots grown in 5 mg kg − 1 Cd-contaminated soil was slightly higher than that of 0.5 mg kg − 1 Cd-contaminated soil, while the Se concentration of stems and pods was lower than 0.5 mg kg − 1 Cd-contaminating the soil. Compared with Cd0.5Se1, Cd5Se1 increased the Se concentration in roots by 6.67%, decreased the Se concentration in stems by 18.60%, significantly decreased the Se concentration in pods by 10.47%, and increased the Se concentration in seeds by 3.92%. Compared with Cd0.5Se5, Cd5Se5 could significant changes in Se concentration in various parts. Among them, the Se concentration in the roots of rape increased by 6.50%, the Se concentration in the stems decreased by 17.12%, the Se concentration in the pods significantly decreased by 9.31%, and the Se concentration in the seeds decreased by 10.98%. Table 5 Se concentration in different parts of rapes grown in soil with different concentrations of Se and Cd. Treatment Se concentration (mg/kg DW) Root Stem Pod Seed Cd0.5 0.02 ± 0.00 d 0.04 ± 0.01 d 0.16 ± 0.02 d 0.06 ± 0.00 d Cd0.5Se0.1 0.08 ± 0.01 d 0.07 ± 0.01 d 0.21 ± 0.01 d 0.11 ± 0.01 d Cd0.5Se1 0.45 ± 0.04 c 0.43 ± 0.03 c 0.86 ± 0.08 c 0.51 ± 0.06 c Cd0.5Se5 2.77 ± 0.07 b 2.57 ± 0.16 a 4.94 ± 0.22 a 4.19 ± 0.15 a Cd5 0.03 ± 0.01 d 0.04 ± 0.01 d 0.20 ± 0.01 d 0.05 ± 0.00 d Cd5Se0.1 0.08 ± 0.01 d 0.06 ± 0.01 d 0.22 ± 0.02 d 0.11 ± 0.01 d Cd5Se1 0.48 ± 0.03 c 0.35 ± 0.02 c 0.77 ± 0.03 c 0.53 ± 0.04 c Cd5Se5 2.95 ± 0.08 a 2.13 ± 0.05 b 4.48 ± 0.29 b 3.73 ± 0.36 b The mean values (± SE) in each column followed by different letters indicated significant difference among different treatments according to two-way ANOVA followed by Duncan multiple comparison ( P < 0.05). Table 6 Se accumulation in different parts of rapes grown in soil with different concentrations of Se and Cd. Treatment Se accumulation (µg/plant) Root Stem Pod Seed Cd0.5 0.10 ± 0.01 d 0.44 ± 0.12 d 1.26 ± 0.12 d 0.60 ± 0.05 b Cd0.5Se0.1 0.36 ± 0.04 d 0.63 ± 0.05 d 1.76 ± 0.09 cd 1.09 ± 0.10 b Cd0.5Se1 2.26 ± 0.26 c 4.03 ± 0.35 c 7.22 ± 0.84 b 5.14 ± 0.65 b Cd0.5Se5 12.85 ± 0.47 b 24.64 ± 1.24 a 41.65 ± 1.45 a 41.92 ± 1.38 a Cd5 0.15 ± 0.03 d 0.36 ± 0.06 d 1.95 ± 0.10 cd 0.68 ± 0.07 b Cd5Se0.1 0.30 ± 0.04 d 0.55 ± 0.07 d 1.66 ± 0.22 cd 0.96 ± 0.10 b Cd5Se1 2.10 ± 0.08 c 3.35 ± 0.29 c 6.07 ± 0.56 bc 5.10 ± 0.54 b Cd5Se5 14.49 ± 0.46 a 21.18 ± 0.58 b 41.95 ± 3.72 a 43.65 ± 5.96 a The mean values (± SE) in each column followed by different letters indicated significant difference among different treatments according to two-way ANOVA followed by Duncan multiple comparison ( P < 0.05). Under the same soil Cd level, the accumulation of Se in various parts of rape increased with the increase in exogenous Se levels. The Se accumulation in roots and stems increased significantly in the Se1 and Se5 treatments, and the Se accumulation in pods and seeds increased significantly in the Se5. Under the same Se application level, the Se accumulation in the pods treated with Cd5Se0 increased by 54.76% compared with that in the Cd0.5Se0. The Se accumulation in the pods treated with Cd5 Se1 decreased by 15.93% compared with that in the Cd0.5Se1. The Se accumulation in the roots of the Cd5Se5 was significantly increased by 12.76% compared to the Cd0.5Se5, while the Se accumulation in the stems was significantly decreased by 14.04%. 3.5 Effects of Se on Cd and Se translocation factor in different parts of rapes under Cd stress The translocation factor reflects the transport situation of Cd and Se in different parts of rape. The results showed that the TF root−stem and TF stem−seed of the Cd0.5 treatments were smaller than those of the Cd5 treatments, while the TF stem−pod of the Cd0.5 treatments was significantly higher than that of the Cd5 treatments. In the 0.5 mg kg − 1 Cd-contaminated soil, the exogenous addition of Se significantly increased TF stem−pod , while TF stem−seed did not change much. In the 5 mg kg − 1 Cd-contaminated soil, the exogenous addition of Se significantly decreased in TF root−stem and TF stem−seed , and a slight decrease in TF stem−pod (Table 7 ). Table 7 Translocation factor (TF) and bioconcentration factor (BCF) values for Cd in different parts of rapes grown in soil with different concentrations of Se and Cd. Treatment Cd TF root−stem TF stem−pod TF stem−seed BCF root BCF stem BCF pod BCF seed Cd0.5 0.79 ± 0.14 de 1.50 ± 0.17 b 0.04 ± 0.01 d 4.37 ± 0.43 bc 3.26 ± 0.34 b 4.76 ± 0.28 b 0.13 ± 0.02 c Cd0.5Se0.1 0.90 ± 0.15 de 2.19 ± 0.29 a 0.05 ± 0.01 cd 3.92 ± 0.84 bcd 3.20 ± 0.27 b 6.82 ± 0.51 a 0.15 ± 0.02 c Cd0.5Se1 1.36 ± 0.19 bc 2.27 ± 0.25 a 0.03 ± 0.00 d 2.61 ± 0.29 d 3.41 ± 0.19 b 7.61 ± 0.56 a 0.11 ± 0.00 c Cd0.5Se5 0.51 ± 0.01 e 2.38 ± 0.31 a 0.04 ± 0.00 d 6.46 ± 0.16 a 3.27 ± 0.12 b 7.76 ± 1.05 a 0.11 ± 0.00 c Cd5 1.95 ± 0.22 a 0.60 ± 0.04 c 0.09 ± 0.01 a 3.46 ± 0.26 cd 6.59 ± 0.35 a 3.91 ± 0.12 b 0.56 ± 0.05 a Cd5Se0.1 1.11 ± 0.04 cd 0.54 ± 0.02 c 0.07 ± 0.01 b 5.71 ± 0.23 a 6.33 ± 0.19 a 3.41 ± 0.17 b 0.45 ± 0.06 b Cd5Se1 1.38 ± 0.14 bc 0.51 ± 0.01 c 0.06 ± 0.00 bc 5.17 ± 0.53 ab 6.90 ± 0.06 a 3.54 ± 0.07 b 0.44 ± 0.02 b Cd5Se5 1.72 ± 0.15 ab 0.58 ± 0.02 c 0.07 ± 0.00 ab 3.76 ± 0.43 cd 6.28 ± 0.15 a 3.63 ± 0.07 b 0.45 ± 0.02 b The mean values (± SE) in each column followed by different letters indicated significant difference among different treatments according to two-way ANOVA followed by Duncan multiple comparison ( P < 0.05). The changes in the Se translocation factor in different parts of rape were not significant (Table 8 ). The results indicated that in the 0.5 mg kg − 1 and 5 mg kg − 1 Cd-contaminated soil treatments, with the exogenous Se concentration increased, TF root−stem and TF stem−pod decreased to a certain extent, while TF stem−seed had no significant change. Table 8 Translocation factor (TF) and bioconcentration factor (BCF) values for Se in different parts of rapes grown in soil with different concentrations of Se and Cd. Treatment Se TF root−stem TF stem−pod TF stem−seed BCF root BCF stem BCF pod BCF seed Cd0.5 1.73 ± 0.26 a 4.33 ± 0.99 b 1.66 ± 0.34 a 0.15 ± 0.02 c 0.27 ± 0.06 d 1.00 ± 0.10 b 0.39 ± 0.03 b Cd0.5Se0.1 0.86 ± 0.12 bc 3.17 ± 0.35 bc 1.66 ± 0.23 a 0.32 ± 0.05 b 0.26 ± 0.02 d 0.81 ± 0.05 bc 0.42 ± 0.04 b Cd0.5Se1 0.97 ± 0.07 bc 1.99 ± 0.13 c 1.20 ± 0.18 a 0.39 ± 0.04 b 0.37 ± 0.03 bc 0.74 ± 0.07 c 0.44 ± 0.05 b Cd0.5Se5 0.93 ± 0.06 bc 1.95 ± 0.15 c 1.64 ± 0.06 a 0.54 ± 0.01 a 0.50 ± 0.03 a 0.96 ± 0.04 b 0.81 ± 0.03 a Cd5 1.30 ± 0.22 ab 5.92 ± 0.80 a 1.63 ± 0.30 a 0.18 ± 0.04 c 0.22 ± 0.03 d 1.24 ± 0.04 a 0.34 ± 0.03 b Cd5Se0.1 0.77 ± 0.18 c 3.79 ± 0.08 b 1.89 ± 0.11 a 0.32 ± 0.05 b 0.23 ± 0.02 d 0.86 ± 0.09 bc 0.42 ± 0.02 b Cd5Se1 0.74 ± 0.04 c 2.21 ± 0.10 c 1.52 ± 0.05 a 0.41 ± 0.03 b 0.30 ± 0.02 cd 0.66 ± 0.02 c 0.46 ± 0.04 b Cd5Se5 0.72 ± 0.02 c 2.10 ± 0.09 c 1.76 ± 0.13 a 0.57 ± 0.01 a 0.41 ± 0.01 ab 0.87 ± 0.06 bc 0.72 ± 0.07 a The mean values (± SE) in each column followed by different letters indicated significant difference among different treatments according to two-way ANOVA followed by Duncan multiple comparison ( P < 0.05). 4. Discussion Cd is not an essential nutrient for rape plants, and it is normally toxic. In Brassica napus L., there was no significant reduction in biomass under Cd treatment up to a range of 60 mg kg − 1 (dry weight) in leaves [ 37 ]. This corroborates the idea that this species is one of the most tolerant to Cd [ 38 ]. However, excessive accumulation of Cd in rapes, posing a substantial threat to plant growth and human health through dietary intake [ 39 , 40 ]. Therefore, we need to reduce the Cd content in food and increase the selenium content. In this study, the Cd concentration in the seed was reduced to Chinese food safety standards (< 0.1 mg kg − 1 ) (Table 3 ). In addition to the effect of reducing Cd concentration, Se application also significantly increased the Se concentration in rape. Therefore, from the food safety perspective, food produced in this way significantly reduces the risks posed by Cd to human health. Changes in plant biomass are important indicators of the phytotoxicity of Cd [ 8 ]. In the experiment, rapes planted in the test soils were able to grow, flower and produce seeds during the whole growth stage. Although plants could grow vigorously without visible symptoms of Cd phytotoxicity [ 41 ], Cd inhibited plant growth and caused loss of plant dry weights were found in different crops [ 42 , 43 ]. At the Se level of 0.1 or 1 mg kg − 1 , the biomass of root, pod and seed showed a downtrend with the enhanced Cd level. While at the Se level of 0 or 5 mg kg − 1 , the dry weights showed a rising trend with the enhanced Cd level (Table 1 ). Previous study also found that the biomass of some wheat genotypes was increased if treated with Cd, which might be related to the genotype influence [ 44 ]. The dry weight variation induced by Cd was different among the four different parts of rape. Similar phenomenon was also found in the shoot and root of pepper under Cd stress conditions [ 45 ]. The dry weight of different tissue changed during the five growth stages of rice under Cd stress. The present experiment only investigated the mature period of rape, experiments should be conducted to find more variation of plant dry weights at all growth stages of rape treated with Se and Cd. Currently, one of the main effects of Cd toxicity observed in most plants is the inhibition of photosynthesis in the plants [ 46 – 48 ]. Photosynthesis plays an important role in plant biosynthesis, providing an interactive link between the plants internal metabolism and the external environment, and changes in photosynthesis can clearly reflect the initial symptoms of environmental stress [ 49 ]. In this experiment, compared with the treatments without Cd, the presence of Cd had an adverse effect on the photosynthetic pigment content of two different varieties of rape, and the effect was significant under high-Cd stress (Table 2 ). Applying Se to other crops stressed by Cd has also found that the content of photosynthetic pigments in plants increases, and the photosynthetic performance was improved, which is beneficial to plant growth [ 29 , 50 , 51 ]. This may be because Se counteracts the destructive effects of Cd to a certain extent by rebuilding the damaged chloroplast ultrastructure, reorganizing the structure of thylakoids and stroma, increasing chloroplast size and cell membrane fluidity, and preventing chlorophyll degradation. Increases photosynthetic product synthesis and ultimately maintains plant growth [ 52 , 53 ]. In addition, Se can induce the accumulation of photosynthesis-related proteins that can mediate electron transfer, serve as photoreceptors or play a role in protein biosynthesis in chloroplasts, thus improving photosynthesis and chlorophyll fluorescence properties under Cd stress [ 54 ]. Cd could cause obvious ultrastructural damage to root tip cells, and also has adverse effects on cell quality and ultrastructural integrity [ 53 ]. Mitochondria are one of the main organelles affected by Cd toxicity in plant cells and often exhibit ultrastructural changes under heavy metal stress [ 55 ]. Mitochondrial ultrastructural changes observed in Cd-sensitive cucumber cells were symptoms of altered energy status leading to reduced ATP levels under Cd stress conditions [ 56 ]. In addition, studies have shown that the destruction of ultrastructure is related to strong oxidative stress caused by heavy metal-induced generation of excessive ROS [ 55 , 57 ]. Under the Cd stress conditions, ROS production often exceeds the overall cellular antioxidant capacity and causes oxidative damage to different cellular components, such as membrane lipids, proteins, and cellular nucleic acids [ 44 , 55 ]. Exogenous Se can reduce the production of ROS, thus maintaining the integrity of membrane structure and function and increasing membrane stability, thereby improving plant growth [ 16 , 58 ]. In this experiment, we found that the root cells of rape contained a large amount of black precipitate. We speculated that the black precipitate was a complex formed by Se and Cd, which can reduce the toxicity of Cd to cells (Fig. 1 ). In addition, chemical staining of root tip tissue revealed that the increase in Cd stress level caused varying degrees of membrane damage to the root system, while Se had a certain alleviating effect on this damage (Fig. 2 ). These results indicate that exogenous Se could scavenge free radicals produced in roots and maintain root growth under Cd stress. Se application could mitigate the adverse effects of Cd on plant growth [ 29 , 59 ], which was consistent with the results of rape biomass at the low Cd level (Table 3 ). It was observed in rice that the genetic factors of different varieties and the exposure levels of Cd and Se determine the accumulation of Cd in rice, and when the Cd level exceeds 2.0 mg kg − 1 , Se reduces the accumulation of Cd in rice [ 31 ]. In winter wheat, it was found that increasing the supply of Se significantly reduced the Cd content in the plant, especially under moderate Cd stress (Cd 5 µmol/L). In addition, due to different parts of the rice plant, Se reduced the accumulation of Cd in rice husks, stems, leaves and seeds, but did not reduce the accumulation of Cd in rice roots [ 60 ]. Some studies have also found that spraying selenite increases the accumulation of Cd in tobacco leaves, indicating a synergistic effect between Se and Cd [ 27 ]. Therefore, the impact of Se-Cd interaction on Cd accumulation in plants is not only related to the exposure levels of Cd and Se, but also to different plant species, different varieties, and different plant parts [ 28 , 31 , 61 , 62 ]. The level of soil-applied Se in this experiment showed the potential to reduce Cd accumulation and TF stem−seed in rape, which may provide some basis for exploring effective measures to reduce Cd accumulation in rape (Table 7 ). 5. Conclusion The study used pot experiments to explore the response of Se to rape growth and root tip cells under Cd stress. The results showed that application of Se improved the adverse effects of Cd stress on plants. Se increase the dry weight of various parts of rapes under Cd stress. At the same time, the photosynthetic pigment content of rape leaves also increased to varying degrees. In addition, the black precipitates were produced through metal complexation reaction between Se and Cd, thereby reducing the toxic effect of Cd. Furthermore, Se alleviates Cd stress-induced root membrane damage and free radical accumulation in the rape, thus maintaining the growth of rape roots. These results provide an effective strategy for reducing Cd accumulation and enhancing growth in the rape under Cd stress. Declarations Conflict of interest The authors declare that there are no conflicts of interest. Funding This work was supported by Key Laboratory of Eco-geochemistry, Ministry of Natural Resources (No. ZSDHJJ202304), Opening Fund of the State Key Laboratory of Environmental Geochemical (SKLEG2024225), special found of Xinjiang Key Laboratory of Soil and Plant Ecological Processes (23XJTRZW02), the Fundamental Research Funds for the Central Universities (226-2023-00077), the National Key Research and Development Program of China (2023YFD1900904), the Science and Technology Research Project of Hubei Province(D20234501), the Foundation of Talent Introduction Project of Hubei Polytechnic University (23xjz05R), the Funding for Scientific Research Projects from Wuhan Municipal Health Commission (WY22B04). Author Contribution Cixing He conceptualize the manuscript, Cixing He and Yuanyuan Zhao developed the methodology, Cixing He and Tingqinag Li did software related works and validate the results, Cixing He and Chengxiao Hu performed the formal analysis, Cixing He and Zhen Wang conducted the investigation, Cixing He and Jiliang Lü searched the resources, Cixing He and Liqiang Ge conducted the data curation, Cixing He and Chao Xu prepared the original draft, performed data visualization and reviewed and edited the manuscript, Cixing He supervised the work, Cixing He acted as project administrator, Xiaohu Zhao conducted the funding acquisition. All authors have read and agreed to the published version of the manuscript. Data availability Data will be made available on request. References Kubier A, Wilkin RT, Pichler T (2019) Cadmium in soils and groundwater: A review. Appl Geochem 108. https://doi.org/10.1016/j.apgeochem.2019.104388 Qin SY, Liu HG, Nie ZJ, Rengel Z, Gao W, Li C, Zhao P (2020) Toxicity of cadmium and its competition with mineral nutrients for uptake by plants: A review. Pedosphere 30(2):168–180. https://doi.org/10.1016/s1002-0160(20)60002-9 Wang P, Chen HP, Kopittke PM, Zhao FJ (2019) Cadmium contamination in agricultural soils of China and the impact on food safety. Environ Pollut 249:1038–1048. https://doi.org/10.1016/j.envpol.2019.03.063 Kumar S, Sharma A (2019) Cadmium toxicity: effects on human reproduction and fertility. Rev Environ Health 34(4):327–338. https://doi.org/10.1515/reveh-2019-0016 Satarug S, Vesey DA, Gobe GC, Phelps KR (2023) Estimation of health risks associated with dietary cadmium exposure. Arch Toxicol 97(2):329–358. https://doi.org/10.1007/s00204-022-03432-w Li ZM, Liang Y, Hu HW, Shaheen SM, Zhong H, Tack FMG, Zhao JT (2021) Speciation, transportation, and pathways of cadmium in soil-rice systems: A review on the environmental implications and remediation approaches for food safety. Environ Int 156. https://doi.org/10.1016/j.envint.2021.106749 Chen DM, Chen DQ, Xue RR, Long J, Lin XH, Lin YB, Song YY (2019) Effects of boron, silicon and their interactions on cadmium accumulation and toxicity in rice plants. J Hazard Mater 367:447–455. https://doi.org/10.1016/j.jhazmat.2018.12.111 Li YL, Rahman SU, Qiu ZX, Shahzad SM, Nawaz MF, Huang JZ, Cheng HF (2023) Toxic effects of cadmium on the physiological and biochemical attributes of plants, and phytoremediation strategies: A review. Environ Pollut 325. https://doi.org/10.1016/j.envpol.2023.121433 Altaf MA, Shahid R, Ren MX, Naz S, Altaf MM, Khan LU, Shakoor A (2022) Melatonin Mitigates Cadmium Toxicity by Promoting Root Architecture and Mineral Homeostasis of Tomato Genotypes. J Soil Sci Plant Nutr 22(1):1112–1128. https://doi.org/10.1007/s42729-021-00720-9 Gao ZY, Shan DX, He JH, Huang T, Mao Y, Tan HP, Xie TP (2023) Effects and mechanism on cadmium adsorption removal by CaCl2-modified biochar from selenium-rich straw. Bioresour Technol 370. https://doi.org/10.1016/j.biortech.2022.128563 Huang HL, Li M, Rizwan M, Dai ZH, Yuan Y, Hossain MM, Tu SX (2021) Synergistic effect of silicon and selenium on the alleviation of cadmium toxicity in rice plants. J Hazard Mater 401. https://doi.org/10.1016/j.jhazmat.2020.123393 Kumar A, Subrahmanyam G, Mondal R, Cabral-Pinto MMS, Shabnam AA, Jigyasu DK, Yu ZG (2021) Bio-remediation approaches for alleviation of cadmium contamination in natural resources. Chemosphere 268. https://doi.org/10.1016/j.chemosphere.2020.128855 Yuanan H, Hefa C, Shu T (2016) The challenges and solutions for cadmium-contaminated rice in China: a critical review. Environ Int 92–93:515–532. htpps://doi.org/10.1016/j.envint.2016.04.042 Hongping C, Wenwen Z, Xinping Y, Peng W, McGrath SP, Fang-Jie Z (2018) Effective methods to reduce cadmium accumulation in rice grain. Chemosphere 207:699–707. htpps://doi.org/10.1016/j.chemosphere.2018.05.143 Zhao FJ, Tang Z, Song JJ, Huang XY, Wang P (2022) Toxic metals and metalloids: Uptake, transport, detoxification, phytoremediation, and crop improvement for safer food. Mol Plant 15(1):27–44. https://doi.org/10.1016/j.molp.2021.09.016 Lai X, Yang X, Rao S, Zhu Z, Cong X, Ye J, Xu F (2022) Advances in physiological mechanisms of selenium to improve heavy metal stress tolerance in plants. Plant Biol 24(6):913–919. https://doi.org/10.1111/plb.13435 Gu XZ, Wen X, Yi N, Liu YH, Wu J, Li HD, Liu GQ (2022) Effect of foliar application of silicon, selenium and zinc on heavy metal accumulation in wheat grains in field studies. Environ Pollutants Bioavailab 34(1):246–252. https://doi.org/10.1080/26395940.2022.2085630 Liu HD, Xiao CM, Qiu TC, Deng J, Cheng H, Cong X, Zhang Y (2023) Selenium Regulates Antioxidant, Photosynthesis, and Cell Permeability in Plants under Various Abiotic Stresses: A Review. Plants-Basel 12(1). https://doi.org/10.3390/plants12010044 Liu ML, Cao WL, Gao P, Zhao JH, Muhammad U, Ni S, Zuo SM (2022) Effects of two different selenium fertilizers on accumulation of selenium and heavy metals in rice grains in field trials. Food Sci Technol 42. https://doi.org/10.1590/fst.117521 Sun HY, Dai HX, Wang XY, Wang GH (2016) Physiological and proteomic analysis of selenium-mediated tolerance to Cd stress in cucumber ( Cucumis sativus L). Ecotoxicol Environ Saf 133:114–126. https://doi.org/10.1016/j.ecoenv.2016.07.003 Min G, Jun Z, Hailong L, Wantong Z, Yuanmei H, Jiani L, Jing Z (2018) Foliar spraying with silicon and selenium reduces cadmium uptake and mitigates cadmium toxicity in rice. Sci Total Environ 631–632. https://doi.org/10.1016/j.scitotenv.2018.03.047 Kang YY, Qin HY, Wang GH, Lei BF, Yang X, Zhong M (2024) Selenium Nanoparticles Mitigate Cadmium Stress in Tomato through Enhanced Accumulation and Transport of Sulfate/Selenite and Polyamines. J Agric Food Chem 72(3):1473–1486. https://doi.org/10.1021/acs.jafc.3c07504 Wan YN, Yu Y, Wang Q, Qiao YH, Li HF (2016) Cadmium uptake dynamics and translocation in rice seedling: Influence of different forms of selenium. Ecotoxicol Environ Saf 133:127–134. https://doi.org/10.1016/j.ecoenv.2016.07.001 Di X, Jing R, Qin X, Wei Y, Liang X, Wang L, Huang Q (2023) Transcriptome analysis reveals the molecular mechanism of different forms of selenium in reducing cadmium uptake and accumulation in wheat seedlings. Chemosphere 340:139888. https://doi.org/10.1016/j.chemosphere.2023.139888 Cui JH, Liu TX, Li YD, Li FB (2018) Selenium reduces cadmium uptake into rice suspension cells by regulating the expression of lignin synthesis and cadmium-related genes. Sci Total Environ 644:602–610. https://doi.org/10.1016/j.scitotenv.2018.07.002 Muhammad R, Muhammad K, Muhammad R, Shafaqat A, Aasma P, Zaffar M, Xiurong W (2021) Cadmium uptake and translocation: selenium and silicon roles in Cd detoxification for the production of low Cd crops: a critical review. Chemosphere 273. https://doi.org/10.1016/j.chemosphere.2021.129690 Yu Y, Wan YN, Wang Q, Li HF (2017) Effect of humic acid-based amendments with foliar application of Zn and Se on Cd accumulation in tobacco. Ecotoxicol Environ Saf 138:286–291. https://doi.org/10.1016/j.ecoenv.2017.01.011 Yao Y, Sili Y, Jian Z, Yanan W, Qi W, Jingsuo Z, Huafen L (2018) Effect of selenium on the uptake kinetics and accumulation of and oxidative stress induced by cadmium in Brassica chinensis. Ecotoxicol Environ Saf 162:571–580. https://doi.org/10.1016/j.ecoenv.2018.07.041 Huang FY, Chen L, Zhou Y, Huang JQ, Wu F, Hu Q, Fang LC (2024) Exogenous selenium promotes cadmium reduction and selenium enrichment in rice: Evidence, mechanisms, and perspectives. J Hazard Mater 476. https://doi.org/10.1016/j.jhazmat.2024.135043 Golubkina NA, Kosheleva OV, Krivenkov LV, Dobrutskaya HG, Nadezhkin S, Caruso G (2017) Intersexual differences in plant growth, yield, mineral composition and antioxidants of spinach ( Spinacia oleracea L.) as affected by selenium form. Sci Hort 225:350–358. https://doi.org/10.1016/j.scienta.2017.07.001 Huang BF, Xin JL, Dai HW, Zhou WJ (2017) Effects of Interaction between Cadmium (Cd) and Selenium (Se) on Grain Yield and Cd and Se Accumulation in a Hybrid Rice ( Oryza sativa ) System. J Agric Food Chem 65(43):9537–9546. https://doi.org/10.1021/acs.jafc.7b03316 Wu ZC, Zhao XH, Sun XC, Tan QL, Tang YF, Nie ZJ, Hu CX (2015) Xylem transport and gene expression play decisive roles in cadmium accumulation in shoots of two oilseed rape cultivars ( Brassica napus ). Chemosphere 119:1217–1223. https://doi.org/10.1016/j.chemosphere.2014.09.099 Zhao YY, He CX, Wu ZC, Liu XW, Cai MM, Jia W, Zhao XH (2019) Selenium reduces cadmium accumulation in seed by increasing cadmium retention in root of oilseed rape ( Brassica napus L). Environ Exp Bot 158:161–170. https://doi.org/10.1016/j.envexpbot.2018.11.017 Tang YN, Zhao YY, Zhou YJ, Li SQ, Wu CH, Shi GY, Zhao XH (2023) Se Ameliorates Cd Toxicity in Oilseed rape ( Brassica napus L.) Seedlings by Inhibiting Cd Transporter Genes and Maintaining root Plasma Membrane Integrity. Bull Environ Contam Toxicol 111(3). https://doi.org/10.1007/s00128-023-03804-7 Wu ZC, Wang FH, Liu S, Du YQ, Li FR, Du RY, Zhao J (2016) Comparative responses to silicon and selenium in relation to cadmium uptake, compartmentation in roots, and xylem transport in flowering Chinese cabbage ( Brassica campestris L. ssp chinensis var. utilis ) under cadmium stress. Environ Exp Bot 131:173–180. https://doi.org/10.1016/j.envexpbot.2016.07.012 Qin XM, Nie ZJ, Liu HE, Zhao P, Qin SY, Shi ZW (2018) Influence of selenium on root morphology and photosynthetic characteristics of winter wheat under cadmium stress. Environ Exp Bot 150:232–239. https://doi.org/10.1016/j.envexpbot.2018.03.024 Selvam A, Wong JWC (2009) Cadmium uptake potential of Brassica napus cocropped with Brassica parachinensis and Zea mays . J Hazard Mater 167(1–3):170–178. https://doi.org/10.1016/j.jhazmat.2008.12.103 Yang GL, Zheng MM, Tan AJ, Liu YT, Feng D, Lv SM (2021) Research on the Mechanisms of Plant Enrichment and Detoxification of Cadmium. Biology-Basel 10(6). https://doi.org/10.3390/biology10060544 Ruoyu W, Panting S, Yahui G, Ping J, Yuliang C, Hang Y, He Q (2023) Cadmium in food: source, distribution and removal. Food Chem 405. https://doi.org/10.1016/j.foodchem.2022.134666 . Part A) Wen-Juan N, Samavia M, Xiao-Min L, Chuntao H, Zhongyi Y (2023) Molecular-Assisted Breeding of Cadmium Pollution-Safe Cultivars. J Agric Food Chem 71(45):16919–16938. https://doi.org/10.1021/acs.jafc.3c04967 Menhas SQ, Yang XJ, Hayat K, Aftab T, Bundschuh J, Arnao MB, Zhou P (2022) Exogenous Melatonin Enhances Cd Tolerance and Phytoremediation Efficiency by Ameliorating Cd-Induced Stress in Oilseed Crops: A Review. J Plant Growth Regul 41(3):922–935. https://doi.org/10.1007/s00344-021-10349-8 Ahmed T, Masood HA, Noman M, Al-Huqail AA, Alghanem SM, Khan MM, Li B (2023) Biogenic silicon nanoparticles mitigate cadmium (Cd) toxicity in rapeseed ( Brassica napus L.) by modulating the cellular oxidative stress metabolism and reducing Cd translocation. J Hazard Mater 459. https://doi.org/10.1016/j.jhazmat.2023.132070 Alyemeni MN, Ahanger MA, Wijaya L, Alam P, Bhardwaj R, Ahmad P (2018) Selenium mitigates cadmium-induced oxidative stress in tomato ( Solanum lycopersicum L.) plants by modulating chlorophyll fluorescence, osmolyte accumulation, and antioxidant system. Protoplasma 255(2):459–469. https:/doi.org/10.1007/s00709-017-1162-4 Zulfiqar U, Jiang WT, Wang XK, Hussain S, Ahmad M, Maqsood MF, Mustafa A (2022) Cadmium Phytotoxicity, Tolerance, and Advanced Remediation Approaches in Agricultural Soils; A Comprehensive Review. Front Plant Sci 13. https://doi.org/10.3389/fpls.2022.773815 Shekari L, Kamelmanesh MM, Mozafariyan M, Hasanuzzaman M, Sadeghi F (2017) Role of selenium in mitigation of cadmium toxicity in pepper grown in hydroponic condition. J Plant Nutr 40(6):761–772. https://doi.org/10.1080/01904167.2016.1161773 Baruah N, Gogoi N, Roy S, Bora P, Chetia J, Zahra N, Farooq M (2023) Phytotoxic Responses and Plant Tolerance Mechanisms to Cadmium Toxicity. J Soil Sci Plant Nutr 23(4):4805–4826. https://doi.org/10.1007/s42729-023-01525-8 Khanna K, Kohli SK, Ohri P, Bhardwaj R, Ahmad P (2022) Agroecotoxicological Aspect of Cd in Soil-Plant System: Uptake, Translocation and Amelioration Strategies. Environ Sci Pollut Res 29(21):30908–30934. https://doi.org/10.1007/s11356-021-18232-5 Sunil S, Ambuj Bhushan J, Rama Shanker D, Pallavi S (2024) Mitigating cadmium accumulation and toxicity in plants: The promising role of nanoparticles. Sci Total Environ 912. https://doi.org/10.1016/j.scitotenv.2023.168826 Zhang HW, Lu LL (2024) Transcription factors involved in plant responses to cadmium-induced oxidative stress. Front Plant Sci 15. https://doi.org/10.3389/fpls.2024.1397289 Luo F, Zhu D, Sun HC, Zou R, Duan WJ, Liu JX, Yan YM (2023) Wheat Selenium-binding protein TaSBP-A enhances cadmium tolerance by decreasing free Cd 2+ and alleviating the oxidative damage and photosynthesis impairment. Front Plant Sci 14. https://doi.org/10.3389/fpls.2023.1103241 Zhang CH, Huang RQ, Zhan NH, Qin LJ (2023) Methyl jasmonate and selenium synergistically mitigative cadmium toxicity in hot pepper ( Capsicum annuum L.) plants by improving antioxidase activities and reducing Cd accumulation. Environ Sci Pollut Res 30(34):82458–82469. https://doi.org/10.1007/s11356-023-28273-7 Wang M, Mu CY, Li YL, Wang YX, Ma WY, Ge CH, Zhou DM (2023) Foliar application of selenium nanoparticles alleviates cadmium toxicity in maize (Zea mays L.) seedlings: Evidence on antioxidant, gene expression, and metabolomics analysis. Sci Total Environ 899. https://doi.org/10.1016/j.scitotenv.2023.165521 Wang CR, Cheng TT, Liu HT, Zhou FY, Zhang JF, Zhang M, Cao T (2021) Nano-selenium controlled cadmium accumulation and improved photosynthesis in indica rice cultivated in lead and cadmium combined paddy soils. J Environ Sci 103:336–346. https://doi.org/10.1016/j.jes.2020.11.005 Cheng B, Zhang J, Wang C, Li J, Chen F, Cao X, Wang Z (2023) Selenium nanomaterials alleviate Brassica chinensis L cadmium stress: Reducing accumulation, regulating microorganisms and activating glutathione metabolism. Chemosphere 344:140320. https://doi.org/10.1016/j.chemosphere.2023.140320 Cuypers A, Vanbuel I, Iven V, Kunnen K, Vandionant S, Huybrechts M, Hendrix S (2023) Cadmium-induced oxidative stress responses and acclimation in plants require fine-tuning of redox biology at subcellular level. Free Radic Biol Med 199:81–96. https://doi.org/10.1016/j.freeradbiomed.2023.02.010 Gzyl J, Przymusinski R, Gwózdz EA (2009) Ultrastructure analysis of cadmium-tolerant and -sensitive cell lines of cucumber (Cucumis sativus L). Plant Cell Tissue Organ Cult 99(2):227–232. https://doi.org/10.1007/s11240-009-9583-1 Goncharuk EA, Zagoskina NV (2023) Heavy Metals, Their Phytotoxicity, and the Role of Phenolic Antioxidants in Plant Stress Responses with Focus on Cadmium. Rev Molecules 28(9). https://doi.org/10.3390/molecules28093921 Qi WY, Li Q, Chen H, Liu J, Xing SF, Xu M, Wang SG (2021) Selenium nanoparticles ameliorate Brassica napus L. cadmium toxicity by inhibiting the respiratory burst and scavenging reactive oxygen species. J Hazard Mater 417. https://doi.org/10.1016/j.jhazmat.2021.125900 Riaz M, Kamran M, Rizwan M, Ali S, Parveen A, Malik Z, Wang XR (2021) Cadmium uptake and translocation: selenium and silicon roles in Cd detoxification for the production of low Cd crops: a critical review. Chemosphere 273. https://doi.org/10.1016/j.chemosphere.2021.129690 Chen MX, Cao L, Song XZ, Wang XY, Qian QP, Liu W (2014) Effect of Iron Plaque and Selenium on Cadmium Uptake and Translocation in Rice Seedlings ( Oryza sativa ) Grown in Solution Culture. Int J Agric Biology 16(6):1159–1164 Feng RW, Wei CY, Tu SX (2013) The roles of selenium in protecting plants against abiotic stresses. Environ Exp Bot 87:58–68. https://doi.org/10.1016/j.envexpbot.2012.09.002 Hawrylak-Nowak B, Dresler S, Wójcik M (2014) Selenium affects physiological parameters and phytochelatins accumulation in cucumber ( Cucumis sativus L.) plants grown under cadmium exposure. Sci Hort 172:10–18. https://doi.org/10.1016/j.scienta.2014.03.040 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-4976345","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":358640989,"identity":"37a5394b-cf81-4cdb-8232-51e6d6a9c29f","order_by":0,"name":"Cixing He","email":"","orcid":"","institution":"Huazhong Agricultural University","correspondingAuthor":false,"prefix":"","firstName":"Cixing","middleName":"","lastName":"He","suffix":""},{"id":358640990,"identity":"11e3010b-ae5f-49fe-a176-b2564745435f","order_by":1,"name":"Yuanyuan Zhao","email":"","orcid":"","institution":"Huazhong Agricultural University","correspondingAuthor":false,"prefix":"","firstName":"Yuanyuan","middleName":"","lastName":"Zhao","suffix":""},{"id":358640991,"identity":"beb4ed46-8c6f-46d3-82ec-3d18cc19cfe3","order_by":2,"name":"Tingqiang Li","email":"","orcid":"","institution":"Zhejiang University","correspondingAuthor":false,"prefix":"","firstName":"Tingqiang","middleName":"","lastName":"Li","suffix":""},{"id":358640992,"identity":"da0b4492-8857-4fe9-a3a0-e0882302c1e5","order_by":3,"name":"Chengxiao Hu","email":"","orcid":"","institution":"Huazhong Agricultural University","correspondingAuthor":false,"prefix":"","firstName":"Chengxiao","middleName":"","lastName":"Hu","suffix":""},{"id":358640993,"identity":"686777e2-7550-4f67-bdb5-9465abcfc9c9","order_by":4,"name":"Zhen Wang","email":"","orcid":"","institution":"Hubei Polytechnic University","correspondingAuthor":false,"prefix":"","firstName":"Zhen","middleName":"","lastName":"Wang","suffix":""},{"id":358640994,"identity":"f4ad03c7-03fd-4157-b3b5-9a7f3a580a1b","order_by":5,"name":"Jiliang Lü","email":"","orcid":"","institution":"Hubei Polytechnic University","correspondingAuthor":false,"prefix":"","firstName":"Jiliang","middleName":"","lastName":"Lü","suffix":""},{"id":358640995,"identity":"f02faff7-4109-4833-a996-612015d8961e","order_by":6,"name":"Liqiang Ge","email":"","orcid":"","institution":"Ministry of Natural Resources","correspondingAuthor":false,"prefix":"","firstName":"Liqiang","middleName":"","lastName":"Ge","suffix":""},{"id":358640996,"identity":"f81fcee1-2b89-4998-ac3c-37b0dc2f1c44","order_by":7,"name":"Chao Xu","email":"","orcid":"","institution":"Xinjiang Agricultural University","correspondingAuthor":false,"prefix":"","firstName":"Chao","middleName":"","lastName":"Xu","suffix":""},{"id":358640997,"identity":"933c89a9-6902-46ba-b792-71ece0db81e5","order_by":8,"name":"Xiaohu Zhao","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA80lEQVRIiWNgGAWjYDACCQY2IGnDwMDM3MAMFTMgRksaUAsjaVoOAzGxWgxutz978KPifDR/O1BLwR+7xAb25m0SDDV3cGqRnHMg3bDnzO3cGYeBWmbwJCc28Bwrk2A49gynFn6JhGMSvG23cxtAWngkmBMbJHLMJBgbDuPUwiaR2Cb5t+1c7nywFoP6xAb5N/i18Esks0nzth3I3QDWknAYaAsPfi2SM9LYpGXOJOduBGo5zHPguHEbT1qxRcIx3FoMbqQ/k3xTYZc77/zhg495/lTL9rMf3njjQw1uLSjgANh3ICKBOA2jYBSMglEwCnAAALRnURWBLFdIAAAAAElFTkSuQmCC","orcid":"","institution":"Huazhong Agricultural University","correspondingAuthor":true,"prefix":"","firstName":"Xiaohu","middleName":"","lastName":"Zhao","suffix":""}],"badges":[],"createdAt":"2024-08-26 08:23:53","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4976345/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4976345/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":65294709,"identity":"71c14740-e22d-4baf-bc67-e49c72ea91bc","added_by":"auto","created_at":"2024-09-25 18:45:35","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":1047663,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eEffects of Se on ultrastructure of root cell in rape under Cd stress. (A): \u003c/strong\u003eCd0.5 treatment. \u003cstrong\u003e(B):\u003c/strong\u003e Cd0.5Se1 treatment. \u003cstrong\u003e(C):\u003c/strong\u003e Cd0.5Se5 treatment. \u003cstrong\u003e(D):\u003c/strong\u003e Cd5 treatment. \u003cstrong\u003e(E): \u003c/strong\u003eCd5Se1 treatment. \u003cstrong\u003e(F): \u003c/strong\u003eCd5Se5 treatment. CW indicates cell wall, M indicates mitochondrion. Bars are 0.5 μm.\u003c/p\u003e","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-4976345/v1/dd53e58ebdaf61953bc211fd.jpeg"},{"id":65294710,"identity":"6a9678a2-3266-44c0-b446-fe2b32daefe5","added_by":"auto","created_at":"2024-09-25 18:45:35","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":1421642,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eEffects of Se on plasma membrane integrity and O\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e2\u003c/strong\u003e\u003c/sub\u003e\u003csup\u003e\u003cstrong\u003e-\u003c/strong\u003e\u003c/sup\u003e\u003cstrong\u003e accumulation in rape under Cd stress. (A): \u003c/strong\u003eEffects of Cd0, Cd0.5 and Cd5 on plasma membrane integrity.\u003cstrong\u003e (B): \u003c/strong\u003eEffects of Cd0, Cd0.5Se1 and Cd5Se5 on plasma membrane integrity.\u003cstrong\u003e (C): \u003c/strong\u003eEffects of Cd0, Cd0.5 and Cd5 on O\u003csub\u003e2\u003c/sub\u003e\u003csup\u003e-\u003c/sup\u003e accumulation.\u003cstrong\u003e (D): \u003c/strong\u003eEffects of Cd0, Cd0.5Se1 and Cd5Se5 on O\u003csub\u003e2\u003c/sub\u003e\u003csup\u003e-\u003c/sup\u003e accumulation.\u003c/p\u003e","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-4976345/v1/3ab052865783262ce7b8ef27.png"},{"id":65294711,"identity":"21f91b5c-b921-4e4b-9788-592983b454bd","added_by":"auto","created_at":"2024-09-25 18:45:35","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":564397,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eThe process of reducing Cd accumulation in rape under Cd stress by Se application.\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"floatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-4976345/v1/db7596709613f03626d73e61.png"},{"id":72848772,"identity":"30b03726-312c-4a5b-9a49-a23e71f01833","added_by":"auto","created_at":"2025-01-02 22:16:23","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":3662448,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4976345/v1/4c72b449-dfef-409f-89ab-08f87fc25168.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Effects of selenium application on reducing cadmium uptake and ameliorates cadmium stress on oilseed rape (Brassica napus L.) in cadmium-contaminated soil","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eCadmium (Cd) is one of the most toxic heavy metals widely present in the environment around the world [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Under natural conditions, Cd is produced mainly through volcanic emissions and rock weathering. At the same time, anthropogenic activities such as mineral mining, waste emissions, garbage incineration and the use of chemical fertilizers can increase the level of Cd contamination in soil, water and air, thereby increasing the level of Cd contamination in the food chain [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Over the past three decades, Chinese rapid industrialization has caused serious concern about the extent of soil pollution, among which Cd pollution has become one of the major environmental issues threatening China\u0026rsquo;s food security and sustainable agricultural development [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. In addition, Cd pollution also threatens the health of animals, plants and humans, and has attracted global attention [\u003cspan additionalcitationids=\"CR5\" citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eAt present, considerable efforts have been made to reduce the accumulation of Cd in crops and soil, including reducing the availability of Cd in the soil, using phytoremediation or soil washing to remove Cd from the soil, and cultivating Cd through breeding or genetic engineering [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Varieties with low accumulation, applying soil amendments, regulating water management, and spraying foliar fertilizers [\u003cspan additionalcitationids=\"CR10 CR11\" citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. However, the limitation of these measures was that they are inconvenient to apply, consume a lot of manpower, material resources and time, cause soil ion imbalance, and some may even damage crop growth and fail to increase crop yields [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Although transgenic approaches could reduce Cd accumulation in crops [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e], concerns about transgenic crops make them less acceptable to the public. Therefore, urgent action is needed for limit the accumulation of Cd in plants and reduce its toxicity.\u003c/p\u003e \u003cp\u003eSelenium (Se) is a mineral nutrient element that has been shown to promote plant growth under adverse conditions and increase tolerance to environmental stresses [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. Studies have shown that Se application could significantly reduce the accumulation of Cd, As and Pb in wheat grains in field experiment [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. Exogenous Se improves the adverse effects of heavy metals on plants by inhibiting the absorption of heavy metals and improving the antioxidant system [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. In addition, Se could also restore the photosynthetic function of plants under heavy metal stress, to promote plant growth [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe effects of Se on plant Cd toxicity have attracted widespread attention from researchers. A large number of studies have reported Se-mediated reduction of Cd accumulation in crops. For example, it was observed in cucumbers that 6 mmol/L selenite treatment reduced the Cd content in cucumber leaves, stems, and roots by 43%, 26%, and 23% [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. Spraying Se in rice reduced the Cd content in grains, stems and roots by 61.6%, 51.0% and 26.9% respectively [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. This is related to Se inhibiting the absorption of Cd by plants and reducing the transport of Cd from roots to shoots [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e, \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. In addition, Se can also affect the accumulation of Cd in plants by changing the subcellular distribution of Cd [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. In rice suspension cells, it was found that Se reduced the Cd content in the cells by regulating the expression of Cd-related genes (\u003cem\u003eOsLCT1\u003c/em\u003e, \u003cem\u003eOsNramp5\u003c/em\u003e, \u003cem\u003eOsNramp1\u003c/em\u003e, \u003cem\u003eOsIRT1\u003c/em\u003e and \u003cem\u003eOsIRT2\u003c/em\u003e), and a large amount of Cd accumulated in the cell wall and reduced the diffusion into the cells [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. Moreover, Se tends to counteract Cd-induced changes in nutrient element content in plants [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e], which may be one of the important mechanisms by which Se alleviates Cd stress. However, there are also some controversial reports on the synergistic effect between Se and Cd. Researchers have found that spraying selenite on tobacco enhanced Cd accumulation in tobacco leaves [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. When the Cd level is low, Se application reduces the Cd content in the above-ground parts of pakchoi, while Se application increases the Cd content under high Cd levels []. Given that the specific regulatory effect of Se on Cd toxicity is affected by a variety of conditions, including the doses of the two elements [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e], the type of Se [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e] and the plant species [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e], etc., the details of these influencing processes still require further study.\u003c/p\u003e \u003cp\u003eExogenous Se could alleviate oxidative stress induced by heavy metals in plants [\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e]. Although this helps to better understand the mode of action of Se in regulating heavy metal accumulation in plants, Se enhances plant resistance to heavy metal stress. The specific mechanisms of resistance are not yet fully understood. Supplying an appropriate amount of Se to plants can effectively reduce the absorption and accumulation of Cd by plants. Since there is a dose-dependent relationship between Cd and Se, in practical applications, it is necessary to consider how the doses of the two elements will directly affect the regulation of Se and Cd toxic effects, the underlying mechanisms of which are unknown. The ability of plants to tolerate and accumulate heavy metals is also closely related to plant species. \u003cem\u003eBrassicaceae\u003c/em\u003e crops have a strong ability to accumulate Se and Cd. We have explained the response of Se application to Cd-sensitive rapes under Cd stress in our previous study. However, the effects and underlying mechanisms of Se application on Cd-tolerance rapes varieties are still unclear. Therefore, this study selected Cd-tolerance of \u003cem\u003eBrassica napus\u003c/em\u003e L. as the research object, focusing on the interaction between Se, Cd and roots, aiming to explore the potential role of exogenous Se in regulating Cd absorption and distribution in rape plants. With this study, we aimed to: (1) investigate the effects of exogenous Se application on the growth and photosynthetic parameters of rape under Cd stress; (2) explore whether Se could restore the structure of rape root tip cells under Cd stress; (3) explore the effects of Se on Cd content and translocation factor in rape plants under Cd stress.\u003c/p\u003e"},{"header":"2. Materials and methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e2.1 Experiment site and soil characterization\u003c/h2\u003e \u003cp\u003eExperiments were carried out in the Micro-Element Research Center at Huazhong Agricultural University (30\u0026ordm;28\u0026prime;26\u0026prime;\u0026prime;N, 114\u0026ordm;2\u0026prime;15\u0026prime;\u0026prime;E), Wuhan, China. The soil was collected from the upper layer (0\u0026ndash;20 cm) of a test field in Huazhong Agricultural University. The characteristics of the tested soil were as follows: pH 5.07, organic matter 23.81 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, available N 110.40 g kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, available P 296.40 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, available K 437.67 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, total Cd 0.24 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, and total Se 0.16 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003e2.2 Experimental design\u003c/h2\u003e \u003cp\u003eTwo levels of Cd (0.5 and 5 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) and four levels of Se (0, 0.1, 1 and 5 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) were arranged in a randomized block design. Cd chloride (CdCl\u003csub\u003e2\u003c/sub\u003e\u0026middot;2.5H\u003csub\u003e2\u003c/sub\u003eO) and sodium Se (Na\u003csub\u003e2\u003c/sub\u003eSeO\u003csub\u003e3\u003c/sub\u003e) of analytical grade were added and mixed thoroughly with soil (5.5 kg), and then placed in plastic pots 22 cm in diameter and 35 cm in height. In order to meet the nutritional needs of the whole growth period, the soil was fertilized with the following macronutrients (g kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e soil): nitrogen (N) 0.2, phosphorus pentoxide (P\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e) 0.15 and potassium oxide (K\u003csub\u003e2\u003c/sub\u003eO) 0.2 supplied in the form of cobalt amide [CO(NH\u003csub\u003e2\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e], ammonium phosphate monobasic (NH\u003csub\u003e4\u003c/sub\u003eH\u003csub\u003e2\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e) and potassium sulphate (K\u003csub\u003e2\u003c/sub\u003eSO\u003csub\u003e4\u003c/sub\u003e) respectively. Besides, the application of microelements (g kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e soil) was 0.025 mg iron ethylenediaminetetraacetic acid (Fe-EDTA), 1.81 mg manganese (II) chloride tetrahydrate (MnCl\u003csub\u003e2\u003c/sub\u003e\u0026middot;4H\u003csub\u003e2\u003c/sub\u003eO), 0.08 mg copper (II) sulfate pentahydrate (CuSO\u003csub\u003e4\u003c/sub\u003e\u0026middot;5H\u003csub\u003e2\u003c/sub\u003eO), 0.22 mg zinc sulfate heptahydrate (ZnSO\u003csub\u003e4\u003c/sub\u003e\u0026middot;7H\u003csub\u003e2\u003c/sub\u003eO) and 2.86 mg boric acid (H\u003csub\u003e3\u003c/sub\u003eBO\u003csub\u003e3\u003c/sub\u003e). All the fertilizers used were analytical grade, and deionized water was used during the period.\u003c/p\u003e \u003cp\u003eRape (\u003cem\u003eBrassica napus\u003c/em\u003e L.) cultivar \u0026lsquo;Zhongshuang 9\u0026rsquo; was used in this study. This species has strong resistance to Cd were based on the preliminary experiments performed by our group [\u003cspan additionalcitationids=\"CR33\" citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e]. Eight treatments were established with four repetitions. Seeds were sowed directly in soil. After two weeks, two healthy and uniform seedlings were selected and left to grow up in each pot. The containers and plants were put under a rainproof shelter. Two whole rape plants were collected from each pot in the mature period. After rinsing with deionized water three times, plants were divided into four parts (root, shoot, pod and seed). One part of the samples were oven dried to a constant weight, weighed and ground into powder before determination. The other part of the sample were stored in the \u0026minus;\u0026thinsp;80 ℃ refrigerator for analysis of physiological indicators.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003e2.3 Total Cd and Se determination\u003c/h2\u003e \u003cp\u003ePlant samples were digested with 10 mL mixture acid (HNO\u003csub\u003e3\u003c/sub\u003e : HClO\u003csub\u003e4\u003c/sub\u003e 9:1, v/v) at an electric plate. After heating up to a clear solution about 1 mL, the solution was diluted to 50 mL by deionized water. The supernatant was subjected to a flame atomic absorption spectrometry (Z-2000, HITACHI, Japan) to detect the total Cd concentration [\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eFor measuring total Se concentration, samples were digested with 10 mL mixture acid (HNO\u003csub\u003e3\u003c/sub\u003e : HClO\u003csub\u003e4\u003c/sub\u003e 9:1, v/v). After heating to almost 1 mL solution left in the flask, 10 mL HCl (1:1, v/v) was added and heated until white smoke appeared. The acid digests were diluted to 50 mL with deionized water. Se concentration in the supernatant was measured by an atomic absorption spectrometer equipped with a hydride generation system (AFS-8220, Beijing Jitian Instruments Co., China) according to the previous method [\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe quality assurance of Cd and Se analysis process was checked by a reference material of plant GBW10015 (GSB-6) purchased from the National Center of Standard Material in China.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003e2.4 Determination of photosynthetic pigment content\u003c/h2\u003e \u003cp\u003eWash and dry the fresh rapeseed leaves. Cut the leaves into small pieces with scissors while avoiding the veins. Weigh about 0.20 g of the fragments and put them into a 25 mL colorimetric tube. Add 25 mL of 95% ethanol and soak the rapeseed in a dark place. The leaf color turns completely white. Using 95% ethanol as a blank control, use the multi-wavelength scanning function of a spectrophotometer (UV-5200) to measure the absorbance value of the soaking solution at 665, 649 and 470 nm. Calculate the contents of chlorophyll a, chlorophyll b and carotenoids, the calculation formula is as follows: \u003cem\u003eC\u003c/em\u003e\u003csub\u003echlorophyll a\u003c/sub\u003e=13.95\u0026times;A\u003csub\u003e665\u003c/sub\u003e-6.88\u0026times;A\u003csub\u003e649\u003c/sub\u003e, \u003cem\u003eC\u003c/em\u003e\u003csub\u003echlorophyll b\u003c/sub\u003e=24.96\u0026times;A\u003csub\u003e649\u003c/sub\u003e-7.32\u0026times;A\u003csub\u003e665\u003c/sub\u003e, \u003cem\u003eC\u003c/em\u003e \u003csub\u003ecarotenoids\u003c/sub\u003e = (1000\u0026times;A\u003csub\u003e470\u003c/sub\u003e-2.05\u0026times;\u003cem\u003eC\u003c/em\u003e\u003csub\u003echlorophyll a\u003c/sub\u003e-114.8\u0026times;\u003cem\u003eC\u003c/em\u003e\u003csub\u003echlorophyll b\u003c/sub\u003e)/245.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003e2.5 Preparation and observation of root transmission electron microscopy sections\u003c/h2\u003e \u003cp\u003eTake the roots of fresh rapeseed samples, wash them with deionized water, and then use a stainless steel blade to cut about 20 root tips about 1\u0026ndash;3 mm long. Immediately place the cut root tip into a fixative (2.5% (v/v) glutaraldehyde in 50 mmol/L sodium phosphate buffer (PBS, pH 6.8)). When preparing samples, the root tips were first washed three times with the same sodium phosphate buffer, and then allowed to stand in 2% osmium tetroxid fixative solution (osmium tetroxid) prepared with 50 mmol/L sodium cacodylate (pH 7.2) for 2 h, and then washed 3 times with sodium phosphate buffer. Subsequently, the samples were dehydrated in 30%, 50%, 70%, 80%, 90%, and 100% ethanol (v/v) for 15 min. The root tip samples were embedded in Epon 812 resin overnight, and then the samples were cut into ultrathin sections of about 80 nm using an ultrathin cryostat (UC6, LEICA, Germany) and placed on a copper grid. The samples were fixed, dehydrated, cut and observed by transmission electron microscope (H-7650, HITACHI, Japan) on the electron microscope platform of Huazhong Agricultural University.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003e2.6 Plasma membrane integrity histochemical staining\u003c/h2\u003e \u003cp\u003eSoak the sample roots in 0.5 mmol/L CaCl\u003csub\u003e2\u003c/sub\u003e (pH 4.5) solution for 5 minutes, then wash and blot dry. Then, the roots were soaked in 4 mL of 0.025% (w/v) Evans blue solution (dissolved in 100 \u0026micro;mol/L CaCl\u003csub\u003e2\u003c/sub\u003e, pH 5.6) for 30 min, and the roots were fully rinsed with sufficient distilled water until no blue color was visible in the water. Cut the root tip and place it on a glass slide. Add a small amount of water and cover it with a coverslip to observe it under an optical microscope.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003e2.7 Statistical analysis of data\u003c/h2\u003e \u003cp\u003eThe translocation factor (TF) and bioconcentration factor of Cd from root to aboveground parts were estimated as follows:\u003c/p\u003e \u003cp\u003eTF\u003csub\u003eroot\u0026minus;stem\u003c/sub\u003e = Cd\u003csub\u003estem\u003c/sub\u003e/Cd\u003csub\u003eroot\u003c/sub\u003e\u003c/p\u003e \u003cp\u003eTF\u003csub\u003estem\u0026minus;pod\u003c/sub\u003e = Cd\u003csub\u003epod\u003c/sub\u003e/Cd\u003csub\u003estem\u003c/sub\u003e\u003c/p\u003e \u003cp\u003eTF\u003csub\u003estem\u0026minus;seed\u003c/sub\u003e = Cd\u003csub\u003eseed\u003c/sub\u003e/Cd\u003csub\u003estem\u003c/sub\u003e\u003c/p\u003e \u003cp\u003eBCF\u0026thinsp;=\u0026thinsp;Cd\u003csub\u003eplant samples\u003c/sub\u003e/Cd\u003csub\u003esoil\u003c/sub\u003e\u003c/p\u003e \u003cp\u003eCd\u003csub\u003eroot\u003c/sub\u003e, Cd\u003csub\u003estem,\u003c/sub\u003e Cd\u003csub\u003epod\u003c/sub\u003e, and Cd\u003csub\u003eseed\u003c/sub\u003e are the concentrations (mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, dry weight) of Cd in the roots, stems, pods, and seeds of rape plants, respectively.\u003c/p\u003e \u003cp\u003eSPSS 26.0 software was used for statistical analysis of all data. The results were analyzed by two-way ANOVA. The mean values of every treatment were conducted a multiple comparisons by the Duncan test (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05). The results are the means\u0026thinsp;\u0026plusmn;\u0026thinsp;SE (standard error) of four replicates. All tables and figures were performed by Excel 2013 and Sigma Plot 12.5.\u003c/p\u003e \u003c/div\u003e"},{"header":"3. Results","content":"\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003e3.1 Effects of Se on plant growth\u003c/h2\u003e \u003cp\u003eIn the mature period, the whole rape plant was divided into four parts, including root, stem, pod and seed. After 20 days of treatment, the effect of each treatment on the growth of rape seedlings was shown in the Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. The results showed that the dry weight of the shoots and roots was significantly increased in the high Cd level (5 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e), which may be toxic effect of Cd on plants. It is worth noting that, with Se levels increased in the soil, the dry weight of shoots and roots was significantly increased under same Cd level. At the low Cd level (0.5 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e), compared with Cd0.5 treatment, Cd0.5Se0.1, Cd0.5Se1 and Cd0.5Se5 increased the biomass of root by 4.71%, 17.85% and 10.27%. At the same time, the pod and seed increased by 5.56%-6.92% and 4.97%-5.48% with the application of Se. At the high Cd level (5 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e), compared with Cd5 treatment, Cd5Se0.1, Cd5Se1 and Cd5Se5 make the biomass of root, pod and seed decreased firstly and increased subsequently.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eDry weight variation in different parts of rapes grown in soil with different concentrations of Se and Cd.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eTreatment\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"4\" nameend=\"c5\" namest=\"c2\"\u003e \u003cp\u003eDry Biomass (g/plant)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRoot\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eStem\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003ePod\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eSeed\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd0.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4.21\u0026thinsp;\u0026plusmn;\u0026thinsp;0.17 cd\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e9.79\u0026thinsp;\u0026plusmn;\u0026thinsp;0.59 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e7.91\u0026thinsp;\u0026plusmn;\u0026thinsp;0.29 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e9.55\u0026thinsp;\u0026plusmn;\u0026thinsp;0.28 c\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd0.5Se0.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4.41\u0026thinsp;\u0026plusmn;\u0026thinsp;0.23 bc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e9.37\u0026thinsp;\u0026plusmn;\u0026thinsp;0.12 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e8.46\u0026thinsp;\u0026plusmn;\u0026thinsp;0.44 bc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e10.07\u0026thinsp;\u0026plusmn;\u0026thinsp;0.95 bc\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd0.5Se1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4.96\u0026thinsp;\u0026plusmn;\u0026thinsp;0.13 ab\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e9.29\u0026thinsp;\u0026plusmn;\u0026thinsp;0.55 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e8.35\u0026thinsp;\u0026plusmn;\u0026thinsp;0.20 bc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e10.07\u0026thinsp;\u0026plusmn;\u0026thinsp;0.20 bc\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd0.5Se5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4.64\u0026thinsp;\u0026plusmn;\u0026thinsp;0.13 abc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e9.63\u0026thinsp;\u0026plusmn;\u0026thinsp;0.23 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e8.45\u0026thinsp;\u0026plusmn;\u0026thinsp;0.24 bc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e10.02\u0026thinsp;\u0026plusmn;\u0026thinsp;0.27 bc\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5.08\u0026thinsp;\u0026plusmn;\u0026thinsp;0.12 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10.18\u0026thinsp;\u0026plusmn;\u0026thinsp;0.39 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e9.82\u0026thinsp;\u0026plusmn;\u0026thinsp;0.22 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e12.50\u0026thinsp;\u0026plusmn;\u0026thinsp;0.21 a\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd5Se0.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3.64\u0026thinsp;\u0026plusmn;\u0026thinsp;0.17 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e9.36\u0026thinsp;\u0026plusmn;\u0026thinsp;0.29 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e7.41\u0026thinsp;\u0026plusmn;\u0026thinsp;0.19 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e8.72\u0026thinsp;\u0026plusmn;\u0026thinsp;0.44 c\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd5Se1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4.45\u0026thinsp;\u0026plusmn;\u0026thinsp;0.36 abc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e9.56\u0026thinsp;\u0026plusmn;\u0026thinsp;0.62 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e7.87\u0026thinsp;\u0026plusmn;\u0026thinsp;0.56 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e9.52\u0026thinsp;\u0026plusmn;\u0026thinsp;0.42 c\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd5Se5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4.92\u0026thinsp;\u0026plusmn;\u0026thinsp;0.21 ab\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e9.93\u0026thinsp;\u0026plusmn;\u0026thinsp;0.36 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e9.35\u0026thinsp;\u0026plusmn;\u0026thinsp;0.48 ab\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e11.25\u0026thinsp;\u0026plusmn;\u0026thinsp;0.68 ab\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003eThe mean values (\u0026plusmn;\u0026thinsp;SE) in each column followed by different letters indicated significant difference among different treatments according to two-way ANOVA followed by Duncan multiple comparison (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05).\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eIn addition, Cd-induced changes in the photosynthetic pigment content of rape seedlings were partially diminished by Se, especially under higher Cd levels (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Under the two Cd levels, the chlorophyll a, chlorophyll b, carotenoid content and total chlorophyll showed an increasing trend with the increase of Se concentration in the soil. In the Cd0.5 treatment, Cd0.5Se1 and Cd0.5Se5 significantly increased the chlorophyll a, chlorophyll b and total chlorophyll content. Compared with Cd0.5, Cd0.5Se0.1, Cd0.5Se1 and Cd0.5Se5 increased the chlorophyll a content by 11.34%, 31.60% and 48.11%, the chlorophyll b content increased by 12.57%, 33.33% and 54.17%, the carotenoid content increased by 6.25%, 25.01% and 37.55%, and the total chlorophyll content increased by 11.62%, 32.00% and 49.51% respectively. In the Cd5 treatment, Cd5Se1 and Cd5Se5 significantly increased chlorophyll a, chlorophyll b, carotenoid content and total chlorophyll content. Compared with Cd5, Cd5Se1 and Cd5Se5 increased the chlorophyll a content by 43.71% and 40.68%, the chlorophyll b content increased by 47.31% and 47.31%, the carotenoid content increased by 35.77% and 35.77%, and the total chlorophyll content increased by 44.52% and 42.18%. These results showed that Se can significantly increase the photosynthetic pigment content of rape leaves under Cd stress.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eEffects of Se on leaf photosynthetic pigment content of rapes under Cd stress.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTreatment\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eChlorophyll a\u003c/p\u003e \u003cp\u003e(mg/g FW)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eChlorophyll b\u003c/p\u003e \u003cp\u003e(mg/g FW)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eCarotenoids\u003c/p\u003e \u003cp\u003e(mg/g FW)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eChlorophyll a\u0026thinsp;+\u0026thinsp;b\u003c/p\u003e \u003cp\u003e(mg/g FW)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.26\u0026thinsp;\u0026plusmn;\u0026thinsp;0.06 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.39\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.25\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.65\u0026thinsp;\u0026plusmn;\u0026thinsp;0.07 a\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd0.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.79\u0026thinsp;\u0026plusmn;\u0026thinsp;0.05 cde\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.24\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02 cd\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.16\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01 bc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.03\u0026thinsp;\u0026plusmn;\u0026thinsp;0.06 cd\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd0.5Se0.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.88\u0026thinsp;\u0026plusmn;\u0026thinsp;0.04 cd\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.27\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01 bc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.17\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01 bc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.15\u0026thinsp;\u0026plusmn;\u0026thinsp;0.05 f\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd0.5Se1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.04\u0026thinsp;\u0026plusmn;\u0026thinsp;0.06 bc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.32\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02 ab\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.21\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02 ab\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.36\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08 b\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd0.5Se5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.17\u0026thinsp;\u0026plusmn;\u0026thinsp;0.09 ab\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.37\u0026thinsp;\u0026plusmn;\u0026thinsp;0.03 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.22\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01 ab\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.54\u0026thinsp;\u0026plusmn;\u0026thinsp;0.12 ab\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.64\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01 de\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.19\u0026thinsp;\u0026plusmn;\u0026thinsp;0.00 de\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.14\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01 bcd\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.83\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02 e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd5Se0.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.58\u0026thinsp;\u0026plusmn;\u0026thinsp;0.03 e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.17\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02 de\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.12\u0026thinsp;\u0026plusmn;\u0026thinsp;0.00 cd\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.78\u0026thinsp;\u0026plusmn;\u0026thinsp;0.04 e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd5Se1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.92\u0026thinsp;\u0026plusmn;\u0026thinsp;0.04 bc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.28\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02 bc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.19\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01 abc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.20\u0026thinsp;\u0026plusmn;\u0026thinsp;0.06 bc\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd5Se5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.90\u0026thinsp;\u0026plusmn;\u0026thinsp;0.06 bc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.28\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02 bc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.19\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01 abc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.18\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08 bc\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStatistical significance\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSe\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\\times\\:\\)\u003c/span\u003e\u003c/span\u003eSe\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003eData are the means of four replicates. The mean values (\u0026plusmn;\u0026thinsp;SE) in each column followed by different letters indicated significance among different treatments according to two-way ANOVA followed by Duncan multiple comparison (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05).\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003e3.2 Effects of Se on root tip cell in rape under Cd stress\u003c/h2\u003e \u003cp\u003eCompared with root tip cells treated with low Cd, the mitochondria of root tip cells treated with high Cd were more swollen, the ridges inside the mitochondria were relatively disordered, and the cell wall shape was irregular. Intuitively, Se did not restore the morphological damage of mitochondria and cell walls induced by Cd, which may be related to the Se and Cd concentrations and treatment time in this experiment. Moreover, some black precipitates were observed in Cd5Se5 treatment rapeseed root cells, which were presumed to be metal precipitate complexes (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eNext, we further explored the effect of Se on the root tip plasma membrane integrity of rapeseed under Cd stress (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). The color depth and distribution of Evans blue reflect the degree of root tip plasma membrane damage. With the Cd concentration increased, the absorption of Evans blue in the root tips increased and showed a darker blue color. Compared with roots treated with Cd alone, the blue color of the root tips treated with Se and Cd was reduced to varying degrees, indicating that Se reduced the plasma membrane damage induced by Cd in roots. Subsequently, we used histochemical staining to study the effect of Se on the accumulation of superoxide ions in rapeseed under Cd stress. NBT reacts with superoxide anions (O\u003csub\u003e2\u003c/sub\u003e\u003csup\u003e\u0026minus;\u003c/sup\u003e) to form a dark blue insoluble formazan compound, which can reflect the degree of accumulation of superoxide ions. With Cd concentration increased, the root tips took on a darker blue color, indicating increased superoxide ion accumulation. Compared with roots treated with Cd alone, the color of the root tips treated with Se and Cd was reduced to varying degrees. These results indicated that Se plays an important role in scavenging Cd-induced reactive oxygen species (ROS) in roots.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e3.3 Effects of Se on Cd concentration and accumulation in different parts of rapes under Cd stress\u003c/p\u003e \u003cp\u003eAfter exogenous Se was added to Cd-contaminated soil, the Cd concentration and accumulation of rapeseed roots, stems, pods and seeds changed to a certain extent (Tables\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e and \u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). Under the 0.5 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e Cd level, with the Se level increases, the Cd concentration in roots and stems first decreases and then increases, the Cd concentration in pods were increased, and the Cd concentration in seeds first increases and then decreases. Compared with the Cd0.5, the Cd concentration in the roots decreased by 10.22% and 40.25% in the Cd0.5Se0.1 and Cd0.5Se1, and increased by 47.99% in the Cd0.5Se5. The stem Cd concentration decreased by 2.07% in the Cd0.5Se0.1 and increased by 4.13% in the Cd0.5Se1. The Cd concentration of the pod increased by 43.18%, 59.94% and 63.07% respectively in the Cd0.5Se0.1, Cd0.5Se1, and Cd0.5Se5. The Cd concentration significantly increased in the Cd0.5Se1 and Cd0.5Se5. The Cd concentration of seed increased by 10% in the Cd0.5Se0.1, and increased significantly in the Cd0.5Se0.1. The Cd0.5Se1 and Cd0.5Se5 decreased the Cd concentration by 20%. For Cd accumulation, with the soil Se level increased, the Cd accumulation in the roots first decreases and then increases, and the Cd accumulation in the pod increases. Compared with Cd0.5, the Cd0.5Se0.1, Cd0.5Se1, and Cd0.5Se5 decreased the Cd accumulation in stems by 6.38%, 1.56%, and 1.56%; the Cd accumulation in pods increased by 55.65%, 70.03% and 77.21%. The Cd accumulation in roots decreased by 4.59% and 30.86% in the Cd0.5Se0.1 and Cd0.5Se1, while it increased by 61.43% in the Cd0.5Se5. The Cd accumulation in seeds increased by 14.74% in the Cd0.5Se0.1, while it decreased by 10.53% and 11.58% in the Cd0.5Se1 and Cd0.5Se5, respectively.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eCd concentration in different parts of rapes grown in soil with different concentrations of Se and Cd.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eTreatment\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"4\" nameend=\"c5\" namest=\"c2\"\u003e \u003cp\u003eCd concentration (mg/kg DW)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRoot\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eStem\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003ePod\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eSeed\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd0.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3.23\u0026thinsp;\u0026plusmn;\u0026thinsp;0.32 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.42\u0026thinsp;\u0026plusmn;\u0026thinsp;0.25 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.52\u0026thinsp;\u0026plusmn;\u0026thinsp;0.21 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.10\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd0.5Se0.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.90\u0026thinsp;\u0026plusmn;\u0026thinsp;0.62 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.37\u0026thinsp;\u0026plusmn;\u0026thinsp;0.20 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5.04\u0026thinsp;\u0026plusmn;\u0026thinsp;0.38 cd\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.11\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd0.5Se1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.93\u0026thinsp;\u0026plusmn;\u0026thinsp;0.22 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.52\u0026thinsp;\u0026plusmn;\u0026thinsp;0.14 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5.63\u0026thinsp;\u0026plusmn;\u0026thinsp;0.41 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.08\u0026thinsp;\u0026plusmn;\u0026thinsp;0.00 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd0.5Se5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4.78\u0026thinsp;\u0026plusmn;\u0026thinsp;0.12 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.42\u0026thinsp;\u0026plusmn;\u0026thinsp;0.09 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5.74\u0026thinsp;\u0026plusmn;\u0026thinsp;0.78 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.08\u0026thinsp;\u0026plusmn;\u0026thinsp;0.00 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e18.13\u0026thinsp;\u0026plusmn;\u0026thinsp;1.38 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e34.51\u0026thinsp;\u0026plusmn;\u0026thinsp;1.81 ab\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e20.49\u0026thinsp;\u0026plusmn;\u0026thinsp;0.63 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2.96\u0026thinsp;\u0026plusmn;\u0026thinsp;0.24 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd5Se0.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e29.92\u0026thinsp;\u0026plusmn;\u0026thinsp;1.19 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e33.17\u0026thinsp;\u0026plusmn;\u0026thinsp;1.00 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e17.88\u0026thinsp;\u0026plusmn;\u0026thinsp;0.90 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2.37\u0026thinsp;\u0026plusmn;\u0026thinsp;0.31 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd5Se1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e27.08\u0026thinsp;\u0026plusmn;\u0026thinsp;2.76 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e36.14\u0026thinsp;\u0026plusmn;\u0026thinsp;0.31 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e18.55\u0026thinsp;\u0026plusmn;\u0026thinsp;0.35 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2.28\u0026thinsp;\u0026plusmn;\u0026thinsp;0.12 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd5Se5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e19.72\u0026thinsp;\u0026plusmn;\u0026thinsp;2.28 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e32.89\u0026thinsp;\u0026plusmn;\u0026thinsp;0.80 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e19.04\u0026thinsp;\u0026plusmn;\u0026thinsp;0.34 ab\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2.37\u0026thinsp;\u0026plusmn;\u0026thinsp;0.12 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003eThe mean values (\u0026plusmn;\u0026thinsp;SE) in each column followed by different letters indicated significant difference among different treatments according to two-way ANOVA followed by Duncan multiple comparison (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05).\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eCd accumulation in different parts of rapes grown in soil with different concentrations of Se and Cd.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eTreatment\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"4\" nameend=\"c5\" namest=\"c2\"\u003e \u003cp\u003eCd accumulation (\u0026micro;g/plant)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRoot\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eStem\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003ePod\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eSeed\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd0.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e13.74\u0026thinsp;\u0026plusmn;\u0026thinsp;1.82 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e23.66\u0026thinsp;\u0026plusmn;\u0026thinsp;3.04 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e27.69\u0026thinsp;\u0026plusmn;\u0026thinsp;1.00 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.95\u0026thinsp;\u0026plusmn;\u0026thinsp;0.15 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd0.5Se0.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e13.11\u0026thinsp;\u0026plusmn;\u0026thinsp;3.46 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e22.15\u0026thinsp;\u0026plusmn;\u0026thinsp;1.66 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e43.10\u0026thinsp;\u0026plusmn;\u0026thinsp;5.33 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.09\u0026thinsp;\u0026plusmn;\u0026thinsp;0.10 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd0.5Se1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e9.50\u0026thinsp;\u0026plusmn;\u0026thinsp;0.86 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e23.29\u0026thinsp;\u0026plusmn;\u0026thinsp;1.18 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e47.08\u0026thinsp;\u0026plusmn;\u0026thinsp;3.82 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.85\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd0.5Se5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e22.18\u0026thinsp;\u0026plusmn;\u0026thinsp;0.76 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e23.29\u0026thinsp;\u0026plusmn;\u0026thinsp;1.04 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e49.07\u0026thinsp;\u0026plusmn;\u0026thinsp;7.98 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.84\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e92.19\u0026thinsp;\u0026plusmn;\u0026thinsp;7.86 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e350.28\u0026thinsp;\u0026plusmn;\u0026thinsp;17.89 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e201.20\u0026thinsp;\u0026plusmn;\u0026thinsp;7.92 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e36.94\u0026thinsp;\u0026plusmn;\u0026thinsp;3.08 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd5Se0.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e109.17\u0026thinsp;\u0026plusmn;\u0026thinsp;7.90 ab\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e310.78\u0026thinsp;\u0026plusmn;\u0026thinsp;17.55 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e132.29\u0026thinsp;\u0026plusmn;\u0026thinsp;7.04 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e20.73\u0026thinsp;\u0026plusmn;\u0026thinsp;3.21 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd5Se1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e120.85\u0026thinsp;\u0026plusmn;\u0026thinsp;17.56 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e345.77\u0026thinsp;\u0026plusmn;\u0026thinsp;23.96 ab\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e146.35\u0026thinsp;\u0026plusmn;\u0026thinsp;12.62 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e21.77\u0026thinsp;\u0026plusmn;\u0026thinsp;1.72 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd5Se5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e95.91\u0026thinsp;\u0026plusmn;\u0026thinsp;7.71 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e325.73\u0026thinsp;\u0026plusmn;\u0026thinsp;5.18 ab\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e177.87\u0026thinsp;\u0026plusmn;\u0026thinsp;8.78 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e26.61\u0026thinsp;\u0026plusmn;\u0026thinsp;1.74 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003eThe mean values (\u0026plusmn;\u0026thinsp;SE) in each column followed by different letters indicated significant difference among different treatments according to two-way ANOVA followed by Duncan multiple comparison (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05).\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eUnder the 5 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e Cd level, with the level of Se increased in soil, the Cd concentration in the roots showed an increasing trend, while the Cd concentration in the pods and seeds showed decreasing trend. The Cd5Se0.1 and Cd5Se1 significantly increased the Cd concentration in roots. Compared with Cd5, the Cd5Se0.1, Cd5Se1 and Cd5Se5 increased the Cd concentration by 65.03%, 49.37% and 8.77% respectively. The Cd concentration was significantly decreased in the Cd5Se0.1 and Cd5Se1 in the pods. The Cd concentration was decreased by 12.74%, 9.47% and 7.07% in the Cd5Se0.1, Cd5Se1 and Cd5Se5. The Cd concentration of the seeds was significantly decreased by 19.93%, 22.97% and 19.93% in the Cd5Se0.1, Cd5Se1 and Cd5Se5. The Cd concentration of stems decreased by 3.88% in the Cd5Se0.1, increased by 4.27% in the Cd5Se1, and decreased by 4.69% in the Cd5Se5. For Cd accumulation, under the 5 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e Cd level, with the soil Se level increased, the Cd accumulation in the roots showed a trend of first increasing and then decreasing, while the Cd accumulation in the stems, pods and seeds were decreased to varying degrees. Compared with Cd5, Cd5Se1 significantly increased the Cd accumulation in roots. In the Cd5Se0.1, Cd5Se1, and Cd5Se5, root Cd accumulation increased by 18.42%, 31.09%, and 4.04%. The Cd5Se0.1 and Cd5Se5 significantly decreased the Cd accumulation in stems by 11.25% and 7.01%. Cd accumulation in pods was significantly decreased by 34.25%, 27.26% and 11.60%. Cd accumulation in seeds was significantly decreased by 43.88%, 41.07% and 27.96%. Taken together, the addition of exogenous Se to soil decreased the Cd concentration in various parts of rape, and significantly decreased the Cd concentration in seeds of rape.\u003c/p\u003e \u003cp\u003e3.4 Effects of Se on Se concentration and accumulation in different parts of rapes under Cd stress\u003c/p\u003e \u003cp\u003eAdding exogenous Se to soil could significantly increase the Se concentration and accumulation in various parts of rape under Cd stress (Tables\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e and \u003cspan refid=\"Tab6\" class=\"InternalRef\"\u003e6\u003c/span\u003e). In the low-Se treatments (Se0.1), the Se concentration of roots, stems, pods, and seeds of rape grown in 5 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e Cd-contaminated soil was similar to the Se concentration of various parts in the 0.5 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e Cd-contaminated soil. In the high-Se treatments (Se1 and Se5), the Se concentration of rape roots grown in 5 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e Cd-contaminated soil was slightly higher than that of 0.5 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e Cd-contaminated soil, while the Se concentration of stems and pods was lower than 0.5 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e Cd-contaminating the soil. Compared with Cd0.5Se1, Cd5Se1 increased the Se concentration in roots by 6.67%, decreased the Se concentration in stems by 18.60%, significantly decreased the Se concentration in pods by 10.47%, and increased the Se concentration in seeds by 3.92%. Compared with Cd0.5Se5, Cd5Se5 could significant changes in Se concentration in various parts. Among them, the Se concentration in the roots of rape increased by 6.50%, the Se concentration in the stems decreased by 17.12%, the Se concentration in the pods significantly decreased by 9.31%, and the Se concentration in the seeds decreased by 10.98%.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eSe concentration in different parts of rapes grown in soil with different concentrations of Se and Cd.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eTreatment\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"4\" nameend=\"c5\" namest=\"c2\"\u003e \u003cp\u003eSe concentration (mg/kg DW)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRoot\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eStem\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003ePod\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eSeed\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd0.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.02\u0026thinsp;\u0026plusmn;\u0026thinsp;0.00 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.04\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.16\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.06\u0026thinsp;\u0026plusmn;\u0026thinsp;0.00 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd0.5Se0.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.08\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.07\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.21\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.11\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd0.5Se1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.45\u0026thinsp;\u0026plusmn;\u0026thinsp;0.04 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.43\u0026thinsp;\u0026plusmn;\u0026thinsp;0.03 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.86\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.51\u0026thinsp;\u0026plusmn;\u0026thinsp;0.06 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd0.5Se5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.77\u0026thinsp;\u0026plusmn;\u0026thinsp;0.07 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.57\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4.94\u0026thinsp;\u0026plusmn;\u0026thinsp;0.22 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4.19\u0026thinsp;\u0026plusmn;\u0026thinsp;0.15 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.03\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.04\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.20\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.05\u0026thinsp;\u0026plusmn;\u0026thinsp;0.00 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd5Se0.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.08\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.06\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.22\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.11\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd5Se1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.48\u0026thinsp;\u0026plusmn;\u0026thinsp;0.03 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.35\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.77\u0026thinsp;\u0026plusmn;\u0026thinsp;0.03 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.53\u0026thinsp;\u0026plusmn;\u0026thinsp;0.04 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd5Se5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.95\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.13\u0026thinsp;\u0026plusmn;\u0026thinsp;0.05 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4.48\u0026thinsp;\u0026plusmn;\u0026thinsp;0.29 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3.73\u0026thinsp;\u0026plusmn;\u0026thinsp;0.36 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003eThe mean values (\u0026plusmn;\u0026thinsp;SE) in each column followed by different letters indicated significant difference among different treatments according to two-way ANOVA followed by Duncan multiple comparison (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05).\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab6\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 6\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eSe accumulation in different parts of rapes grown in soil with different concentrations of Se and Cd.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eTreatment\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"4\" nameend=\"c6\" namest=\"c3\"\u003e \u003cp\u003eSe accumulation (\u0026micro;g/plant)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eRoot\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eStem\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003ePod\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eSeed\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd0.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.10\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.44\u0026thinsp;\u0026plusmn;\u0026thinsp;0.12 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.26\u0026thinsp;\u0026plusmn;\u0026thinsp;0.12 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.60\u0026thinsp;\u0026plusmn;\u0026thinsp;0.05 b\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd0.5Se0.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.36\u0026thinsp;\u0026plusmn;\u0026thinsp;0.04 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.63\u0026thinsp;\u0026plusmn;\u0026thinsp;0.05 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.76\u0026thinsp;\u0026plusmn;\u0026thinsp;0.09 cd\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1.09\u0026thinsp;\u0026plusmn;\u0026thinsp;0.10 b\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd0.5Se1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.26\u0026thinsp;\u0026plusmn;\u0026thinsp;0.26 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4.03\u0026thinsp;\u0026plusmn;\u0026thinsp;0.35 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e7.22\u0026thinsp;\u0026plusmn;\u0026thinsp;0.84 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e5.14\u0026thinsp;\u0026plusmn;\u0026thinsp;0.65 b\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd0.5Se5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e12.85\u0026thinsp;\u0026plusmn;\u0026thinsp;0.47 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e24.64\u0026thinsp;\u0026plusmn;\u0026thinsp;1.24 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e41.65\u0026thinsp;\u0026plusmn;\u0026thinsp;1.45 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e41.92\u0026thinsp;\u0026plusmn;\u0026thinsp;1.38 a\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.15\u0026thinsp;\u0026plusmn;\u0026thinsp;0.03 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.36\u0026thinsp;\u0026plusmn;\u0026thinsp;0.06 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.95\u0026thinsp;\u0026plusmn;\u0026thinsp;0.10 cd\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.68\u0026thinsp;\u0026plusmn;\u0026thinsp;0.07 b\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd5Se0.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.30\u0026thinsp;\u0026plusmn;\u0026thinsp;0.04 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.55\u0026thinsp;\u0026plusmn;\u0026thinsp;0.07 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.66\u0026thinsp;\u0026plusmn;\u0026thinsp;0.22 cd\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.96\u0026thinsp;\u0026plusmn;\u0026thinsp;0.10 b\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd5Se1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.10\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.35\u0026thinsp;\u0026plusmn;\u0026thinsp;0.29 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e6.07\u0026thinsp;\u0026plusmn;\u0026thinsp;0.56 bc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e5.10\u0026thinsp;\u0026plusmn;\u0026thinsp;0.54 b\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd5Se5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e14.49\u0026thinsp;\u0026plusmn;\u0026thinsp;0.46 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e21.18\u0026thinsp;\u0026plusmn;\u0026thinsp;0.58 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e41.95\u0026thinsp;\u0026plusmn;\u0026thinsp;3.72 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e43.65\u0026thinsp;\u0026plusmn;\u0026thinsp;5.96 a\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003eThe mean values (\u0026plusmn;\u0026thinsp;SE) in each column followed by different letters indicated significant difference among different treatments according to two-way ANOVA followed by Duncan multiple comparison (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05).\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eUnder the same soil Cd level, the accumulation of Se in various parts of rape increased with the increase in exogenous Se levels. The Se accumulation in roots and stems increased significantly in the Se1 and Se5 treatments, and the Se accumulation in pods and seeds increased significantly in the Se5. Under the same Se application level, the Se accumulation in the pods treated with Cd5Se0 increased by 54.76% compared with that in the Cd0.5Se0. The Se accumulation in the pods treated with Cd5 Se1 decreased by 15.93% compared with that in the Cd0.5Se1. The Se accumulation in the roots of the Cd5Se5 was significantly increased by 12.76% compared to the Cd0.5Se5, while the Se accumulation in the stems was significantly decreased by 14.04%.\u003c/p\u003e \u003cp\u003e3.5 Effects of Se on Cd and Se translocation factor in different parts of rapes under Cd stress\u003c/p\u003e \u003cp\u003eThe translocation factor reflects the transport situation of Cd and Se in different parts of rape. The results showed that the TF\u003csub\u003eroot\u0026minus;stem\u003c/sub\u003e and TF\u003csub\u003estem\u0026minus;seed\u003c/sub\u003e of the Cd0.5 treatments were smaller than those of the Cd5 treatments, while the TF\u003csub\u003estem\u0026minus;pod\u003c/sub\u003e of the Cd0.5 treatments was significantly higher than that of the Cd5 treatments. In the 0.5 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e Cd-contaminated soil, the exogenous addition of Se significantly increased TF\u003csub\u003estem\u0026minus;pod\u003c/sub\u003e, while TF\u003csub\u003estem\u0026minus;seed\u003c/sub\u003e did not change much. In the 5 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e Cd-contaminated soil, the exogenous addition of Se significantly decreased in TF\u003csub\u003eroot\u0026minus;stem\u003c/sub\u003e and TF\u003csub\u003estem\u0026minus;seed\u003c/sub\u003e, and a slight decrease in TF\u003csub\u003estem\u0026minus;pod\u003c/sub\u003e (Table\u0026nbsp;\u003cspan refid=\"Tab7\" class=\"InternalRef\"\u003e7\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab7\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 7\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eTranslocation factor (TF) and bioconcentration factor (BCF) values for Cd in different parts of rapes grown in soil with different concentrations of Se and Cd.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"8\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eTreatment\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"7\" nameend=\"c8\" namest=\"c2\"\u003e \u003cp\u003eCd\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTF\u003csub\u003eroot\u0026minus;stem\u003c/sub\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eTF\u003csub\u003estem\u0026minus;pod\u003c/sub\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eTF\u003csub\u003estem\u0026minus;seed\u003c/sub\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eBCF\u003csub\u003eroot\u003c/sub\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eBCF\u003csub\u003estem\u003c/sub\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eBCF\u003csub\u003epod\u003c/sub\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003eBCF\u003csub\u003eseed\u003c/sub\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd0.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.79\u0026thinsp;\u0026plusmn;\u0026thinsp;0.14 de\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.50\u0026thinsp;\u0026plusmn;\u0026thinsp;0.17 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.04\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4.37\u0026thinsp;\u0026plusmn;\u0026thinsp;0.43 bc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e3.26\u0026thinsp;\u0026plusmn;\u0026thinsp;0.34 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e4.76\u0026thinsp;\u0026plusmn;\u0026thinsp;0.28 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.13\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02 c\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd0.5Se0.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.90\u0026thinsp;\u0026plusmn;\u0026thinsp;0.15 de\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.19\u0026thinsp;\u0026plusmn;\u0026thinsp;0.29 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.05\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01 cd\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3.92\u0026thinsp;\u0026plusmn;\u0026thinsp;0.84 bcd\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e3.20\u0026thinsp;\u0026plusmn;\u0026thinsp;0.27 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e6.82\u0026thinsp;\u0026plusmn;\u0026thinsp;0.51 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.15\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02 c\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd0.5Se1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.36\u0026thinsp;\u0026plusmn;\u0026thinsp;0.19 bc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.27\u0026thinsp;\u0026plusmn;\u0026thinsp;0.25 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.03\u0026thinsp;\u0026plusmn;\u0026thinsp;0.00 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2.61\u0026thinsp;\u0026plusmn;\u0026thinsp;0.29 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e3.41\u0026thinsp;\u0026plusmn;\u0026thinsp;0.19 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e7.61\u0026thinsp;\u0026plusmn;\u0026thinsp;0.56 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.11\u0026thinsp;\u0026plusmn;\u0026thinsp;0.00 c\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd0.5Se5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.51\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01 e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.38\u0026thinsp;\u0026plusmn;\u0026thinsp;0.31 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.04\u0026thinsp;\u0026plusmn;\u0026thinsp;0.00 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e6.46\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e3.27\u0026thinsp;\u0026plusmn;\u0026thinsp;0.12 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e7.76\u0026thinsp;\u0026plusmn;\u0026thinsp;1.05 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.11\u0026thinsp;\u0026plusmn;\u0026thinsp;0.00 c\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.95\u0026thinsp;\u0026plusmn;\u0026thinsp;0.22 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.60\u0026thinsp;\u0026plusmn;\u0026thinsp;0.04 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.09\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3.46\u0026thinsp;\u0026plusmn;\u0026thinsp;0.26 cd\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e6.59\u0026thinsp;\u0026plusmn;\u0026thinsp;0.35 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e3.91\u0026thinsp;\u0026plusmn;\u0026thinsp;0.12 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.56\u0026thinsp;\u0026plusmn;\u0026thinsp;0.05 a\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd5Se0.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.11\u0026thinsp;\u0026plusmn;\u0026thinsp;0.04 cd\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.54\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.07\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e5.71\u0026thinsp;\u0026plusmn;\u0026thinsp;0.23 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e6.33\u0026thinsp;\u0026plusmn;\u0026thinsp;0.19 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e3.41\u0026thinsp;\u0026plusmn;\u0026thinsp;0.17 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.45\u0026thinsp;\u0026plusmn;\u0026thinsp;0.06 b\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd5Se1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.38\u0026thinsp;\u0026plusmn;\u0026thinsp;0.14 bc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.51\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.06\u0026thinsp;\u0026plusmn;\u0026thinsp;0.00 bc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e5.17\u0026thinsp;\u0026plusmn;\u0026thinsp;0.53 ab\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e6.90\u0026thinsp;\u0026plusmn;\u0026thinsp;0.06 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e3.54\u0026thinsp;\u0026plusmn;\u0026thinsp;0.07 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.44\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02 b\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd5Se5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.72\u0026thinsp;\u0026plusmn;\u0026thinsp;0.15 ab\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.58\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.07\u0026thinsp;\u0026plusmn;\u0026thinsp;0.00 ab\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3.76\u0026thinsp;\u0026plusmn;\u0026thinsp;0.43 cd\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e6.28\u0026thinsp;\u0026plusmn;\u0026thinsp;0.15 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e3.63\u0026thinsp;\u0026plusmn;\u0026thinsp;0.07 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.45\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02 b\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"8\"\u003eThe mean values (\u0026plusmn;\u0026thinsp;SE) in each column followed by different letters indicated significant difference among different treatments according to two-way ANOVA followed by Duncan multiple comparison (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05).\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThe changes in the Se translocation factor in different parts of rape were not significant (Table\u0026nbsp;\u003cspan refid=\"Tab8\" class=\"InternalRef\"\u003e8\u003c/span\u003e). The results indicated that in the 0.5 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and 5 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e Cd-contaminated soil treatments, with the exogenous Se concentration increased, TF\u003csub\u003eroot\u0026minus;stem\u003c/sub\u003e and TF\u003csub\u003estem\u0026minus;pod\u003c/sub\u003e decreased to a certain extent, while TF\u003csub\u003estem\u0026minus;seed\u003c/sub\u003e had no significant change.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab8\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 8\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eTranslocation factor (TF) and bioconcentration factor (BCF) values for Se in different parts of rapes grown in soil with different concentrations of Se and Cd.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"8\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eTreatment\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"7\" nameend=\"c8\" namest=\"c2\"\u003e \u003cp\u003eSe\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTF\u003csub\u003eroot\u0026minus;stem\u003c/sub\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eTF\u003csub\u003estem\u0026minus;pod\u003c/sub\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eTF\u003csub\u003estem\u0026minus;seed\u003c/sub\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eBCF\u003csub\u003eroot\u003c/sub\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eBCF\u003csub\u003estem\u003c/sub\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eBCF\u003csub\u003epod\u003c/sub\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003eBCF\u003csub\u003eseed\u003c/sub\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd0.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.73\u0026thinsp;\u0026plusmn;\u0026thinsp;0.26 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4.33\u0026thinsp;\u0026plusmn;\u0026thinsp;0.99 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.66\u0026thinsp;\u0026plusmn;\u0026thinsp;0.34 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.15\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.27\u0026thinsp;\u0026plusmn;\u0026thinsp;0.06 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e1.00\u0026thinsp;\u0026plusmn;\u0026thinsp;0.10 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.39\u0026thinsp;\u0026plusmn;\u0026thinsp;0.03 b\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd0.5Se0.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.86\u0026thinsp;\u0026plusmn;\u0026thinsp;0.12 bc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3.17\u0026thinsp;\u0026plusmn;\u0026thinsp;0.35 bc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.66\u0026thinsp;\u0026plusmn;\u0026thinsp;0.23 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.32\u0026thinsp;\u0026plusmn;\u0026thinsp;0.05 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.26\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.81\u0026thinsp;\u0026plusmn;\u0026thinsp;0.05 bc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.42\u0026thinsp;\u0026plusmn;\u0026thinsp;0.04 b\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd0.5Se1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.97\u0026thinsp;\u0026plusmn;\u0026thinsp;0.07 bc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.99\u0026thinsp;\u0026plusmn;\u0026thinsp;0.13 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.20\u0026thinsp;\u0026plusmn;\u0026thinsp;0.18 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.39\u0026thinsp;\u0026plusmn;\u0026thinsp;0.04 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.37\u0026thinsp;\u0026plusmn;\u0026thinsp;0.03 bc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.74\u0026thinsp;\u0026plusmn;\u0026thinsp;0.07 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.44\u0026thinsp;\u0026plusmn;\u0026thinsp;0.05 b\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd0.5Se5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.93\u0026thinsp;\u0026plusmn;\u0026thinsp;0.06 bc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.95\u0026thinsp;\u0026plusmn;\u0026thinsp;0.15 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.64\u0026thinsp;\u0026plusmn;\u0026thinsp;0.06 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.54\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.50\u0026thinsp;\u0026plusmn;\u0026thinsp;0.03 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.96\u0026thinsp;\u0026plusmn;\u0026thinsp;0.04 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.81\u0026thinsp;\u0026plusmn;\u0026thinsp;0.03 a\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.30\u0026thinsp;\u0026plusmn;\u0026thinsp;0.22 ab\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5.92\u0026thinsp;\u0026plusmn;\u0026thinsp;0.80 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.63\u0026thinsp;\u0026plusmn;\u0026thinsp;0.30 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.18\u0026thinsp;\u0026plusmn;\u0026thinsp;0.04 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.22\u0026thinsp;\u0026plusmn;\u0026thinsp;0.03 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e1.24\u0026thinsp;\u0026plusmn;\u0026thinsp;0.04 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.34\u0026thinsp;\u0026plusmn;\u0026thinsp;0.03 b\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd5Se0.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.77\u0026thinsp;\u0026plusmn;\u0026thinsp;0.18 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3.79\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.89\u0026thinsp;\u0026plusmn;\u0026thinsp;0.11 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.32\u0026thinsp;\u0026plusmn;\u0026thinsp;0.05 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.23\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02 d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.86\u0026thinsp;\u0026plusmn;\u0026thinsp;0.09 bc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.42\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02 b\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd5Se1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.74\u0026thinsp;\u0026plusmn;\u0026thinsp;0.04 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.21\u0026thinsp;\u0026plusmn;\u0026thinsp;0.10 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.52\u0026thinsp;\u0026plusmn;\u0026thinsp;0.05 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.41\u0026thinsp;\u0026plusmn;\u0026thinsp;0.03 b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.30\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02 cd\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.66\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.46\u0026thinsp;\u0026plusmn;\u0026thinsp;0.04 b\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd5Se5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.72\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.10\u0026thinsp;\u0026plusmn;\u0026thinsp;0.09 c\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.76\u0026thinsp;\u0026plusmn;\u0026thinsp;0.13 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.57\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01 a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.41\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01 ab\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.87\u0026thinsp;\u0026plusmn;\u0026thinsp;0.06 bc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.72\u0026thinsp;\u0026plusmn;\u0026thinsp;0.07 a\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"8\"\u003eThe mean values (\u0026plusmn;\u0026thinsp;SE) in each column followed by different letters indicated significant difference among different treatments according to two-way ANOVA followed by Duncan multiple comparison (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05).\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"4. Discussion","content":"\u003cp\u003eCd is not an essential nutrient for rape plants, and it is normally toxic. In \u003cem\u003eBrassica napus\u003c/em\u003e L., there was no significant reduction in biomass under Cd treatment up to a range of 60 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e (dry weight) in leaves [\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e]. This corroborates the idea that this species is one of the most tolerant to Cd [\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e]. However, excessive accumulation of Cd in rapes, posing a substantial threat to plant growth and human health through dietary intake [\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e, \u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e]. Therefore, we need to reduce the Cd content in food and increase the selenium content. In this study, the Cd concentration in the seed was reduced to Chinese food safety standards (\u0026lt;\u0026thinsp;0.1 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). In addition to the effect of reducing Cd concentration, Se application also significantly increased the Se concentration in rape. Therefore, from the food safety perspective, food produced in this way significantly reduces the risks posed by Cd to human health.\u003c/p\u003e \u003cp\u003eChanges in plant biomass are important indicators of the phytotoxicity of Cd [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. In the experiment, rapes planted in the test soils were able to grow, flower and produce seeds during the whole growth stage. Although plants could grow vigorously without visible symptoms of Cd phytotoxicity [\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e], Cd inhibited plant growth and caused loss of plant dry weights were found in different crops [\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e, \u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e]. At the Se level of 0.1 or 1 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, the biomass of root, pod and seed showed a downtrend with the enhanced Cd level. While at the Se level of 0 or 5 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, the dry weights showed a rising trend with the enhanced Cd level (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Previous study also found that the biomass of some wheat genotypes was increased if treated with Cd, which might be related to the genotype influence [\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e]. The dry weight variation induced by Cd was different among the four different parts of rape. Similar phenomenon was also found in the shoot and root of pepper under Cd stress conditions [\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e]. The dry weight of different tissue changed during the five growth stages of rice under Cd stress. The present experiment only investigated the mature period of rape, experiments should be conducted to find more variation of plant dry weights at all growth stages of rape treated with Se and Cd.\u003c/p\u003e \u003cp\u003eCurrently, one of the main effects of Cd toxicity observed in most plants is the inhibition of photosynthesis in the plants [\u003cspan additionalcitationids=\"CR47\" citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e48\u003c/span\u003e]. Photosynthesis plays an important role in plant biosynthesis, providing an interactive link between the plants internal metabolism and the external environment, and changes in photosynthesis can clearly reflect the initial symptoms of environmental stress [\u003cspan citationid=\"CR49\" class=\"CitationRef\"\u003e49\u003c/span\u003e]. In this experiment, compared with the treatments without Cd, the presence of Cd had an adverse effect on the photosynthetic pigment content of two different varieties of rape, and the effect was significant under high-Cd stress (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Applying Se to other crops stressed by Cd has also found that the content of photosynthetic pigments in plants increases, and the photosynthetic performance was improved, which is beneficial to plant growth [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e, \u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e50\u003c/span\u003e, \u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e51\u003c/span\u003e]. This may be because Se counteracts the destructive effects of Cd to a certain extent by rebuilding the damaged chloroplast ultrastructure, reorganizing the structure of thylakoids and stroma, increasing chloroplast size and cell membrane fluidity, and preventing chlorophyll degradation. Increases photosynthetic product synthesis and ultimately maintains plant growth [\u003cspan citationid=\"CR52\" class=\"CitationRef\"\u003e52\u003c/span\u003e, \u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e53\u003c/span\u003e]. In addition, Se can induce the accumulation of photosynthesis-related proteins that can mediate electron transfer, serve as photoreceptors or play a role in protein biosynthesis in chloroplasts, thus improving photosynthesis and chlorophyll fluorescence properties under Cd stress [\u003cspan citationid=\"CR54\" class=\"CitationRef\"\u003e54\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eCd could cause obvious ultrastructural damage to root tip cells, and also has adverse effects on cell quality and ultrastructural integrity [\u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e53\u003c/span\u003e]. Mitochondria are one of the main organelles affected by Cd toxicity in plant cells and often exhibit ultrastructural changes under heavy metal stress [\u003cspan citationid=\"CR55\" class=\"CitationRef\"\u003e55\u003c/span\u003e]. Mitochondrial ultrastructural changes observed in Cd-sensitive cucumber cells were symptoms of altered energy status leading to reduced ATP levels under Cd stress conditions [\u003cspan citationid=\"CR56\" class=\"CitationRef\"\u003e56\u003c/span\u003e]. In addition, studies have shown that the destruction of ultrastructure is related to strong oxidative stress caused by heavy metal-induced generation of excessive ROS [\u003cspan citationid=\"CR55\" class=\"CitationRef\"\u003e55\u003c/span\u003e, \u003cspan citationid=\"CR57\" class=\"CitationRef\"\u003e57\u003c/span\u003e]. Under the Cd stress conditions, ROS production often exceeds the overall cellular antioxidant capacity and causes oxidative damage to different cellular components, such as membrane lipids, proteins, and cellular nucleic acids [\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e, \u003cspan citationid=\"CR55\" class=\"CitationRef\"\u003e55\u003c/span\u003e]. Exogenous Se can reduce the production of ROS, thus maintaining the integrity of membrane structure and function and increasing membrane stability, thereby improving plant growth [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e, \u003cspan citationid=\"CR58\" class=\"CitationRef\"\u003e58\u003c/span\u003e]. In this experiment, we found that the root cells of rape contained a large amount of black precipitate. We speculated that the black precipitate was a complex formed by Se and Cd, which can reduce the toxicity of Cd to cells (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). In addition, chemical staining of root tip tissue revealed that the increase in Cd stress level caused varying degrees of membrane damage to the root system, while Se had a certain alleviating effect on this damage (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). These results indicate that exogenous Se could scavenge free radicals produced in roots and maintain root growth under Cd stress.\u003c/p\u003e \u003cp\u003eSe application could mitigate the adverse effects of Cd on plant growth [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e, \u003cspan citationid=\"CR59\" class=\"CitationRef\"\u003e59\u003c/span\u003e], which was consistent with the results of rape biomass at the low Cd level (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). It was observed in rice that the genetic factors of different varieties and the exposure levels of Cd and Se determine the accumulation of Cd in rice, and when the Cd level exceeds 2.0 mg kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, Se reduces the accumulation of Cd in rice [\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e]. In winter wheat, it was found that increasing the supply of Se significantly reduced the Cd content in the plant, especially under moderate Cd stress (Cd 5 \u0026micro;mol/L). In addition, due to different parts of the rice plant, Se reduced the accumulation of Cd in rice husks, stems, leaves and seeds, but did not reduce the accumulation of Cd in rice roots [\u003cspan citationid=\"CR60\" class=\"CitationRef\"\u003e60\u003c/span\u003e]. Some studies have also found that spraying selenite increases the accumulation of Cd in tobacco leaves, indicating a synergistic effect between Se and Cd [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. Therefore, the impact of Se-Cd interaction on Cd accumulation in plants is not only related to the exposure levels of Cd and Se, but also to different plant species, different varieties, and different plant parts [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e, \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e, \u003cspan citationid=\"CR61\" class=\"CitationRef\"\u003e61\u003c/span\u003e, \u003cspan citationid=\"CR62\" class=\"CitationRef\"\u003e62\u003c/span\u003e]. The level of soil-applied Se in this experiment showed the potential to reduce Cd accumulation and TF\u003csub\u003estem\u0026minus;seed\u003c/sub\u003e in rape, which may provide some basis for exploring effective measures to reduce Cd accumulation in rape (Table\u0026nbsp;\u003cspan refid=\"Tab7\" class=\"InternalRef\"\u003e7\u003c/span\u003e).\u003c/p\u003e"},{"header":"5. Conclusion","content":"\u003cp\u003eThe study used pot experiments to explore the response of Se to rape growth and root tip cells under Cd stress. The results showed that application of Se improved the adverse effects of Cd stress on plants. Se increase the dry weight of various parts of rapes under Cd stress. At the same time, the photosynthetic pigment content of rape leaves also increased to varying degrees. In addition, the black precipitates were produced through metal complexation reaction between Se and Cd, thereby reducing the toxic effect of Cd. Furthermore, Se alleviates Cd stress-induced root membrane damage and free radical accumulation in the rape, thus maintaining the growth of rape roots. These results provide an effective strategy for reducing Cd accumulation and enhancing growth in the rape under Cd stress.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e \u003ch2\u003eConflict of interest\u003c/h2\u003e \u003cp\u003eThe authors declare that there are no conflicts of interest.\u003c/p\u003e \u003c/p\u003e\u003ch2\u003eFunding\u003c/h2\u003e \u003cp\u003eThis work was supported by Key Laboratory of Eco-geochemistry, Ministry of Natural Resources (No. ZSDHJJ202304), Opening Fund of the State Key Laboratory of Environmental Geochemical (SKLEG2024225), special found of Xinjiang Key Laboratory of Soil and Plant Ecological Processes (23XJTRZW02), the Fundamental Research Funds for the Central Universities (226-2023-00077), the National Key Research and Development Program of China (2023YFD1900904), the Science and Technology Research Project of Hubei Province(D20234501), the Foundation of Talent Introduction Project of Hubei Polytechnic University (23xjz05R), the Funding for Scientific Research Projects from Wuhan Municipal Health Commission (WY22B04).\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eCixing He conceptualize the manuscript, Cixing He and Yuanyuan Zhao developed the methodology, Cixing He and Tingqinag Li did software related works and validate the results, Cixing He and Chengxiao Hu performed the formal analysis, Cixing He and Zhen Wang conducted the investigation, Cixing He and Jiliang L\u0026uuml; searched the resources, Cixing He and Liqiang Ge conducted the data curation, Cixing He and Chao Xu prepared the original draft, performed data visualization and reviewed and edited the manuscript, Cixing He supervised the work, Cixing He acted as project administrator, Xiaohu Zhao conducted the funding acquisition. All authors have read and agreed to the published version of the manuscript.\u003c/p\u003e\u003ch2\u003eData availability\u003c/h2\u003e \u003cp\u003eData will be made available on request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eKubier A, Wilkin RT, Pichler T (2019) Cadmium in soils and groundwater: A review. Appl Geochem 108. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.apgeochem.2019.104388\u003c/span\u003e\u003cspan address=\"10.1016/j.apgeochem.2019.104388\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eQin SY, Liu HG, Nie ZJ, Rengel Z, Gao W, Li C, Zhao P (2020) Toxicity of cadmium and its competition with mineral nutrients for uptake by plants: A review. Pedosphere 30(2):168\u0026ndash;180. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/s1002-0160(20)60002-9\u003c/span\u003e\u003cspan address=\"10.1016/s1002-0160(20)60002-9\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang P, Chen HP, Kopittke PM, Zhao FJ (2019) Cadmium contamination in agricultural soils of China and the impact on food safety. Environ Pollut 249:1038\u0026ndash;1048. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.envpol.2019.03.063\u003c/span\u003e\u003cspan address=\"10.1016/j.envpol.2019.03.063\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKumar S, Sharma A (2019) Cadmium toxicity: effects on human reproduction and fertility. Rev Environ Health 34(4):327\u0026ndash;338. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1515/reveh-2019-0016\u003c/span\u003e\u003cspan address=\"10.1515/reveh-2019-0016\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSatarug S, Vesey DA, Gobe GC, Phelps KR (2023) Estimation of health risks associated with dietary cadmium exposure. Arch Toxicol 97(2):329\u0026ndash;358. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s00204-022-03432-w\u003c/span\u003e\u003cspan address=\"10.1007/s00204-022-03432-w\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi ZM, Liang Y, Hu HW, Shaheen SM, Zhong H, Tack FMG, Zhao JT (2021) Speciation, transportation, and pathways of cadmium in soil-rice systems: A review on the environmental implications and remediation approaches for food safety. Environ Int 156. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.envint.2021.106749\u003c/span\u003e\u003cspan address=\"10.1016/j.envint.2021.106749\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChen DM, Chen DQ, Xue RR, Long J, Lin XH, Lin YB, Song YY (2019) Effects of boron, silicon and their interactions on cadmium accumulation and toxicity in rice plants. J Hazard Mater 367:447\u0026ndash;455. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.jhazmat.2018.12.111\u003c/span\u003e\u003cspan address=\"10.1016/j.jhazmat.2018.12.111\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi YL, Rahman SU, Qiu ZX, Shahzad SM, Nawaz MF, Huang JZ, Cheng HF (2023) Toxic effects of cadmium on the physiological and biochemical attributes of plants, and phytoremediation strategies: A review. Environ Pollut 325. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.envpol.2023.121433\u003c/span\u003e\u003cspan address=\"10.1016/j.envpol.2023.121433\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAltaf MA, Shahid R, Ren MX, Naz S, Altaf MM, Khan LU, Shakoor A (2022) Melatonin Mitigates Cadmium Toxicity by Promoting Root Architecture and Mineral Homeostasis of Tomato Genotypes. J Soil Sci Plant Nutr 22(1):1112\u0026ndash;1128. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s42729-021-00720-9\u003c/span\u003e\u003cspan address=\"10.1007/s42729-021-00720-9\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGao ZY, Shan DX, He JH, Huang T, Mao Y, Tan HP, Xie TP (2023) Effects and mechanism on cadmium adsorption removal by CaCl2-modified biochar from selenium-rich straw. Bioresour Technol 370. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.biortech.2022.128563\u003c/span\u003e\u003cspan address=\"10.1016/j.biortech.2022.128563\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHuang HL, Li M, Rizwan M, Dai ZH, Yuan Y, Hossain MM, Tu SX (2021) Synergistic effect of silicon and selenium on the alleviation of cadmium toxicity in rice plants. J Hazard Mater 401. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.jhazmat.2020.123393\u003c/span\u003e\u003cspan address=\"10.1016/j.jhazmat.2020.123393\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKumar A, Subrahmanyam G, Mondal R, Cabral-Pinto MMS, Shabnam AA, Jigyasu DK, Yu ZG (2021) Bio-remediation approaches for alleviation of cadmium contamination in natural resources. Chemosphere 268. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.chemosphere.2020.128855\u003c/span\u003e\u003cspan address=\"10.1016/j.chemosphere.2020.128855\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYuanan H, Hefa C, Shu T (2016) The challenges and solutions for cadmium-contaminated rice in China: a critical review. Environ Int 92\u0026ndash;93:515\u0026ndash;532. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehtpps://doi.org/10.1016/j.envint.2016.04.042\u003c/span\u003e\u003cspan address=\"htpps://10.1016/j.envint.2016.04.042\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHongping C, Wenwen Z, Xinping Y, Peng W, McGrath SP, Fang-Jie Z (2018) Effective methods to reduce cadmium accumulation in rice grain. Chemosphere 207:699\u0026ndash;707. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehtpps://doi.org/10.1016/j.chemosphere.2018.05.143\u003c/span\u003e\u003cspan address=\"htpps://10.1016/j.chemosphere.2018.05.143\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhao FJ, Tang Z, Song JJ, Huang XY, Wang P (2022) Toxic metals and metalloids: Uptake, transport, detoxification, phytoremediation, and crop improvement for safer food. Mol Plant 15(1):27\u0026ndash;44. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.molp.2021.09.016\u003c/span\u003e\u003cspan address=\"10.1016/j.molp.2021.09.016\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLai X, Yang X, Rao S, Zhu Z, Cong X, Ye J, Xu F (2022) Advances in physiological mechanisms of selenium to improve heavy metal stress tolerance in plants. Plant Biol 24(6):913\u0026ndash;919. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1111/plb.13435\u003c/span\u003e\u003cspan address=\"10.1111/plb.13435\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGu XZ, Wen X, Yi N, Liu YH, Wu J, Li HD, Liu GQ (2022) Effect of foliar application of silicon, selenium and zinc on heavy metal accumulation in wheat grains in field studies. Environ Pollutants Bioavailab 34(1):246\u0026ndash;252. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1080/26395940.2022.2085630\u003c/span\u003e\u003cspan address=\"10.1080/26395940.2022.2085630\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLiu HD, Xiao CM, Qiu TC, Deng J, Cheng H, Cong X, Zhang Y (2023) Selenium Regulates Antioxidant, Photosynthesis, and Cell Permeability in Plants under Various Abiotic Stresses: A Review. Plants-Basel 12(1). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3390/plants12010044\u003c/span\u003e\u003cspan address=\"10.3390/plants12010044\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLiu ML, Cao WL, Gao P, Zhao JH, Muhammad U, Ni S, Zuo SM (2022) Effects of two different selenium fertilizers on accumulation of selenium and heavy metals in rice grains in field trials. Food Sci Technol 42. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1590/fst.117521\u003c/span\u003e\u003cspan address=\"10.1590/fst.117521\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSun HY, Dai HX, Wang XY, Wang GH (2016) Physiological and proteomic analysis of selenium-mediated tolerance to Cd stress in cucumber (\u003cem\u003eCucumis sativus\u003c/em\u003e L). Ecotoxicol Environ Saf 133:114\u0026ndash;126. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.ecoenv.2016.07.003\u003c/span\u003e\u003cspan address=\"10.1016/j.ecoenv.2016.07.003\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMin G, Jun Z, Hailong L, Wantong Z, Yuanmei H, Jiani L, Jing Z (2018) Foliar spraying with silicon and selenium reduces cadmium uptake and mitigates cadmium toxicity in rice. Sci Total Environ 631\u0026ndash;632. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.scitotenv.2018.03.047\u003c/span\u003e\u003cspan address=\"10.1016/j.scitotenv.2018.03.047\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKang YY, Qin HY, Wang GH, Lei BF, Yang X, Zhong M (2024) Selenium Nanoparticles Mitigate Cadmium Stress in Tomato through Enhanced Accumulation and Transport of Sulfate/Selenite and Polyamines. J Agric Food Chem 72(3):1473\u0026ndash;1486. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1021/acs.jafc.3c07504\u003c/span\u003e\u003cspan address=\"10.1021/acs.jafc.3c07504\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWan YN, Yu Y, Wang Q, Qiao YH, Li HF (2016) Cadmium uptake dynamics and translocation in rice seedling: Influence of different forms of selenium. Ecotoxicol Environ Saf 133:127\u0026ndash;134. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.ecoenv.2016.07.001\u003c/span\u003e\u003cspan address=\"10.1016/j.ecoenv.2016.07.001\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDi X, Jing R, Qin X, Wei Y, Liang X, Wang L, Huang Q (2023) Transcriptome analysis reveals the molecular mechanism of different forms of selenium in reducing cadmium uptake and accumulation in wheat seedlings. Chemosphere 340:139888. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.chemosphere.2023.139888\u003c/span\u003e\u003cspan address=\"10.1016/j.chemosphere.2023.139888\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCui JH, Liu TX, Li YD, Li FB (2018) Selenium reduces cadmium uptake into rice suspension cells by regulating the expression of lignin synthesis and cadmium-related genes. Sci Total Environ 644:602\u0026ndash;610. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.scitotenv.2018.07.002\u003c/span\u003e\u003cspan address=\"10.1016/j.scitotenv.2018.07.002\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMuhammad R, Muhammad K, Muhammad R, Shafaqat A, Aasma P, Zaffar M, Xiurong W (2021) Cadmium uptake and translocation: selenium and silicon roles in Cd detoxification for the production of low Cd crops: a critical review. Chemosphere 273. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.chemosphere.2021.129690\u003c/span\u003e\u003cspan address=\"10.1016/j.chemosphere.2021.129690\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYu Y, Wan YN, Wang Q, Li HF (2017) Effect of humic acid-based amendments with foliar application of Zn and Se on Cd accumulation in tobacco. Ecotoxicol Environ Saf 138:286\u0026ndash;291. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.ecoenv.2017.01.011\u003c/span\u003e\u003cspan address=\"10.1016/j.ecoenv.2017.01.011\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYao Y, Sili Y, Jian Z, Yanan W, Qi W, Jingsuo Z, Huafen L (2018) Effect of selenium on the uptake kinetics and accumulation of and oxidative stress induced by cadmium in Brassica chinensis. Ecotoxicol Environ Saf 162:571\u0026ndash;580. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.ecoenv.2018.07.041\u003c/span\u003e\u003cspan address=\"10.1016/j.ecoenv.2018.07.041\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHuang FY, Chen L, Zhou Y, Huang JQ, Wu F, Hu Q, Fang LC (2024) Exogenous selenium promotes cadmium reduction and selenium enrichment in rice: Evidence, mechanisms, and perspectives. J Hazard Mater 476. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.jhazmat.2024.135043\u003c/span\u003e\u003cspan address=\"10.1016/j.jhazmat.2024.135043\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGolubkina NA, Kosheleva OV, Krivenkov LV, Dobrutskaya HG, Nadezhkin S, Caruso G (2017) Intersexual differences in plant growth, yield, mineral composition and antioxidants of spinach (\u003cem\u003eSpinacia oleracea\u003c/em\u003e L.) as affected by selenium form. Sci Hort 225:350\u0026ndash;358. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.scienta.2017.07.001\u003c/span\u003e\u003cspan address=\"10.1016/j.scienta.2017.07.001\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHuang BF, Xin JL, Dai HW, Zhou WJ (2017) Effects of Interaction between Cadmium (Cd) and Selenium (Se) on Grain Yield and Cd and Se Accumulation in a Hybrid Rice (\u003cem\u003eOryza sativa\u003c/em\u003e) System. J Agric Food Chem 65(43):9537\u0026ndash;9546. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1021/acs.jafc.7b03316\u003c/span\u003e\u003cspan address=\"10.1021/acs.jafc.7b03316\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWu ZC, Zhao XH, Sun XC, Tan QL, Tang YF, Nie ZJ, Hu CX (2015) Xylem transport and gene expression play decisive roles in cadmium accumulation in shoots of two oilseed rape cultivars (\u003cem\u003eBrassica napus\u003c/em\u003e). Chemosphere 119:1217\u0026ndash;1223. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.chemosphere.2014.09.099\u003c/span\u003e\u003cspan address=\"10.1016/j.chemosphere.2014.09.099\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhao YY, He CX, Wu ZC, Liu XW, Cai MM, Jia W, Zhao XH (2019) Selenium reduces cadmium accumulation in seed by increasing cadmium retention in root of oilseed rape (\u003cem\u003eBrassica napus\u003c/em\u003e L). Environ Exp Bot 158:161\u0026ndash;170. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.envexpbot.2018.11.017\u003c/span\u003e\u003cspan address=\"10.1016/j.envexpbot.2018.11.017\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTang YN, Zhao YY, Zhou YJ, Li SQ, Wu CH, Shi GY, Zhao XH (2023) Se Ameliorates Cd Toxicity in Oilseed rape (\u003cem\u003eBrassica napus\u003c/em\u003e L.) Seedlings by Inhibiting Cd Transporter Genes and Maintaining root Plasma Membrane Integrity. Bull Environ Contam Toxicol 111(3). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s00128-023-03804-7\u003c/span\u003e\u003cspan address=\"10.1007/s00128-023-03804-7\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWu ZC, Wang FH, Liu S, Du YQ, Li FR, Du RY, Zhao J (2016) Comparative responses to silicon and selenium in relation to cadmium uptake, compartmentation in roots, and xylem transport in flowering Chinese cabbage (\u003cem\u003eBrassica campestris\u003c/em\u003e L. ssp \u003cem\u003echinensis\u003c/em\u003e var. \u003cem\u003eutilis\u003c/em\u003e) under cadmium stress. Environ Exp Bot 131:173\u0026ndash;180. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.envexpbot.2016.07.012\u003c/span\u003e\u003cspan address=\"10.1016/j.envexpbot.2016.07.012\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eQin XM, Nie ZJ, Liu HE, Zhao P, Qin SY, Shi ZW (2018) Influence of selenium on root morphology and photosynthetic characteristics of winter wheat under cadmium stress. Environ Exp Bot 150:232\u0026ndash;239. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.envexpbot.2018.03.024\u003c/span\u003e\u003cspan address=\"10.1016/j.envexpbot.2018.03.024\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSelvam A, Wong JWC (2009) Cadmium uptake potential of \u003cem\u003eBrassica napus\u003c/em\u003e cocropped with \u003cem\u003eBrassica parachinensis\u003c/em\u003e and \u003cem\u003eZea mays\u003c/em\u003e. J Hazard Mater 167(1\u0026ndash;3):170\u0026ndash;178. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.jhazmat.2008.12.103\u003c/span\u003e\u003cspan address=\"10.1016/j.jhazmat.2008.12.103\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYang GL, Zheng MM, Tan AJ, Liu YT, Feng D, Lv SM (2021) Research on the Mechanisms of Plant Enrichment and Detoxification of Cadmium. Biology-Basel 10(6). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3390/biology10060544\u003c/span\u003e\u003cspan address=\"10.3390/biology10060544\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRuoyu W, Panting S, Yahui G, Ping J, Yuliang C, Hang Y, He Q (2023) Cadmium in food: source, distribution and removal. Food Chem 405. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.foodchem.2022.134666\u003c/span\u003e\u003cspan address=\"10.1016/j.foodchem.2022.134666\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. Part A)\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWen-Juan N, Samavia M, Xiao-Min L, Chuntao H, Zhongyi Y (2023) Molecular-Assisted Breeding of Cadmium Pollution-Safe Cultivars. J Agric Food Chem 71(45):16919\u0026ndash;16938. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1021/acs.jafc.3c04967\u003c/span\u003e\u003cspan address=\"10.1021/acs.jafc.3c04967\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMenhas SQ, Yang XJ, Hayat K, Aftab T, Bundschuh J, Arnao MB, Zhou P (2022) Exogenous Melatonin Enhances Cd Tolerance and Phytoremediation Efficiency by Ameliorating Cd-Induced Stress in Oilseed Crops: A Review. J Plant Growth Regul 41(3):922\u0026ndash;935. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s00344-021-10349-8\u003c/span\u003e\u003cspan address=\"10.1007/s00344-021-10349-8\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAhmed T, Masood HA, Noman M, Al-Huqail AA, Alghanem SM, Khan MM, Li B (2023) Biogenic silicon nanoparticles mitigate cadmium (Cd) toxicity in rapeseed (\u003cem\u003eBrassica napus\u003c/em\u003e L.) by modulating the cellular oxidative stress metabolism and reducing Cd translocation. J Hazard Mater 459. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.jhazmat.2023.132070\u003c/span\u003e\u003cspan address=\"10.1016/j.jhazmat.2023.132070\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAlyemeni MN, Ahanger MA, Wijaya L, Alam P, Bhardwaj R, Ahmad P (2018) Selenium mitigates cadmium-induced oxidative stress in tomato (\u003cem\u003eSolanum lycopersicum\u003c/em\u003e L.) plants by modulating chlorophyll fluorescence, osmolyte accumulation, and antioxidant system. Protoplasma 255(2):459\u0026ndash;469. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps:/doi.org/10.1007/s00709-017-1162-4\u003c/span\u003e\u003cspan address=\"10.1007/s00709-017-1162-4\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZulfiqar U, Jiang WT, Wang XK, Hussain S, Ahmad M, Maqsood MF, Mustafa A (2022) Cadmium Phytotoxicity, Tolerance, and Advanced Remediation Approaches in Agricultural Soils; A Comprehensive Review. Front Plant Sci 13. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3389/fpls.2022.773815\u003c/span\u003e\u003cspan address=\"10.3389/fpls.2022.773815\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eShekari L, Kamelmanesh MM, Mozafariyan M, Hasanuzzaman M, Sadeghi F (2017) Role of selenium in mitigation of cadmium toxicity in pepper grown in hydroponic condition. J Plant Nutr 40(6):761\u0026ndash;772. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1080/01904167.2016.1161773\u003c/span\u003e\u003cspan address=\"10.1080/01904167.2016.1161773\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBaruah N, Gogoi N, Roy S, Bora P, Chetia J, Zahra N, Farooq M (2023) Phytotoxic Responses and Plant Tolerance Mechanisms to Cadmium Toxicity. J Soil Sci Plant Nutr 23(4):4805\u0026ndash;4826. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s42729-023-01525-8\u003c/span\u003e\u003cspan address=\"10.1007/s42729-023-01525-8\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKhanna K, Kohli SK, Ohri P, Bhardwaj R, Ahmad P (2022) Agroecotoxicological Aspect of Cd in Soil-Plant System: Uptake, Translocation and Amelioration Strategies. Environ Sci Pollut Res 29(21):30908\u0026ndash;30934. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s11356-021-18232-5\u003c/span\u003e\u003cspan address=\"10.1007/s11356-021-18232-5\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSunil S, Ambuj Bhushan J, Rama Shanker D, Pallavi S (2024) Mitigating cadmium accumulation and toxicity in plants: The promising role of nanoparticles. Sci Total Environ 912. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.scitotenv.2023.168826\u003c/span\u003e\u003cspan address=\"10.1016/j.scitotenv.2023.168826\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhang HW, Lu LL (2024) Transcription factors involved in plant responses to cadmium-induced oxidative stress. Front Plant Sci 15. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3389/fpls.2024.1397289\u003c/span\u003e\u003cspan address=\"10.3389/fpls.2024.1397289\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLuo F, Zhu D, Sun HC, Zou R, Duan WJ, Liu JX, Yan YM (2023) Wheat Selenium-binding protein TaSBP-A enhances cadmium tolerance by decreasing free Cd\u003csup\u003e2+\u003c/sup\u003e and alleviating the oxidative damage and photosynthesis impairment. Front Plant Sci 14. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3389/fpls.2023.1103241\u003c/span\u003e\u003cspan address=\"10.3389/fpls.2023.1103241\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhang CH, Huang RQ, Zhan NH, Qin LJ (2023) Methyl jasmonate and selenium synergistically mitigative cadmium toxicity in hot pepper (\u003cem\u003eCapsicum annuum\u003c/em\u003e L.) plants by improving antioxidase activities and reducing Cd accumulation. Environ Sci Pollut Res 30(34):82458\u0026ndash;82469. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s11356-023-28273-7\u003c/span\u003e\u003cspan address=\"10.1007/s11356-023-28273-7\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang M, Mu CY, Li YL, Wang YX, Ma WY, Ge CH, Zhou DM (2023) Foliar application of selenium nanoparticles alleviates cadmium toxicity in maize (Zea mays L.) seedlings: Evidence on antioxidant, gene expression, and metabolomics analysis. Sci Total Environ 899. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.scitotenv.2023.165521\u003c/span\u003e\u003cspan address=\"10.1016/j.scitotenv.2023.165521\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang CR, Cheng TT, Liu HT, Zhou FY, Zhang JF, Zhang M, Cao T (2021) Nano-selenium controlled cadmium accumulation and improved photosynthesis in indica rice cultivated in lead and cadmium combined paddy soils. J Environ Sci 103:336\u0026ndash;346. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.jes.2020.11.005\u003c/span\u003e\u003cspan address=\"10.1016/j.jes.2020.11.005\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCheng B, Zhang J, Wang C, Li J, Chen F, Cao X, Wang Z (2023) Selenium nanomaterials alleviate Brassica chinensis L cadmium stress: Reducing accumulation, regulating microorganisms and activating glutathione metabolism. Chemosphere 344:140320. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.chemosphere.2023.140320\u003c/span\u003e\u003cspan address=\"10.1016/j.chemosphere.2023.140320\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCuypers A, Vanbuel I, Iven V, Kunnen K, Vandionant S, Huybrechts M, Hendrix S (2023) Cadmium-induced oxidative stress responses and acclimation in plants require fine-tuning of redox biology at subcellular level. Free Radic Biol Med 199:81\u0026ndash;96. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.freeradbiomed.2023.02.010\u003c/span\u003e\u003cspan address=\"10.1016/j.freeradbiomed.2023.02.010\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGzyl J, Przymusinski R, Gw\u0026oacute;zdz EA (2009) Ultrastructure analysis of cadmium-tolerant and -sensitive cell lines of cucumber (Cucumis sativus L). Plant Cell Tissue Organ Cult 99(2):227\u0026ndash;232. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s11240-009-9583-1\u003c/span\u003e\u003cspan address=\"10.1007/s11240-009-9583-1\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGoncharuk EA, Zagoskina NV (2023) Heavy Metals, Their Phytotoxicity, and the Role of Phenolic Antioxidants in Plant Stress Responses with Focus on Cadmium. Rev Molecules 28(9). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3390/molecules28093921\u003c/span\u003e\u003cspan address=\"10.3390/molecules28093921\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eQi WY, Li Q, Chen H, Liu J, Xing SF, Xu M, Wang SG (2021) Selenium nanoparticles ameliorate \u003cem\u003eBrassica napus\u003c/em\u003e L. cadmium toxicity by inhibiting the respiratory burst and scavenging reactive oxygen species. J Hazard Mater 417. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.jhazmat.2021.125900\u003c/span\u003e\u003cspan address=\"10.1016/j.jhazmat.2021.125900\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRiaz M, Kamran M, Rizwan M, Ali S, Parveen A, Malik Z, Wang XR (2021) Cadmium uptake and translocation: selenium and silicon roles in Cd detoxification for the production of low Cd crops: a critical review. Chemosphere 273. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.chemosphere.2021.129690\u003c/span\u003e\u003cspan address=\"10.1016/j.chemosphere.2021.129690\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChen MX, Cao L, Song XZ, Wang XY, Qian QP, Liu W (2014) Effect of Iron Plaque and Selenium on Cadmium Uptake and Translocation in Rice Seedlings (\u003cem\u003eOryza sativa\u003c/em\u003e) Grown in Solution Culture. Int J Agric Biology 16(6):1159\u0026ndash;1164\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFeng RW, Wei CY, Tu SX (2013) The roles of selenium in protecting plants against abiotic stresses. Environ Exp Bot 87:58\u0026ndash;68. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.envexpbot.2012.09.002\u003c/span\u003e\u003cspan address=\"10.1016/j.envexpbot.2012.09.002\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHawrylak-Nowak B, Dresler S, W\u0026oacute;jcik M (2014) Selenium affects physiological parameters and phytochelatins accumulation in cucumber (\u003cem\u003eCucumis sativus\u003c/em\u003e L.) plants grown under cadmium exposure. Sci Hort 172:10\u0026ndash;18. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.scienta.2014.03.040\u003c/span\u003e\u003cspan address=\"10.1016/j.scienta.2014.03.040\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Cadmium, Selenium, Brassica napus L., Photosynthetic pigment, Root tips, Reactive oxygen species","lastPublishedDoi":"10.21203/rs.3.rs-4976345/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4976345/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eCadmium is considered a highly toxic metallic element that does not have any beneficial biological functions for humans or plants. It has been reported that the antagonism of selenium to heavy metal stress has been observed in a variety of plants, and appropriate selenium could alleviate heavy metal-induced oxidative damage and reduce the accumulation of heavy metals in plants. The changes of physiological characteristics, root tip cells, cadmium concentration and accumulation of rape under cadmium stress were investigated in this study through pot experiment. Results showed that selenium could alleviate the inhibitory effect of cadmium on the growth of rape seedlings. The concentration and accumulation of cadmium were decreased after the selenium application in rape seeds, ranging from 19.93 to 22.97% and 27.96 to 43.88% respectively. And the decrease of photosynthetic pigment content induced by cadmium was significantly improved. The results of transmission electron microscopy showed that exogenous selenium and cadmium had metal complexation reaction and formed black precipitation, which may be related to the detoxification effect of selenium on cadmium. More critically, with the addition of selenium, the plasma membrane damage and free radical accumulation in root tips induced by cadmium stress were gradually alleviated in the histochemical staining experiment of rape root tips. These results may provide evidence for exploring effective measures to reduce cadmium accumulation in rape under cadmium-contaminated areas.\u003c/p\u003e","manuscriptTitle":"Effects of selenium application on reducing cadmium uptake and ameliorates cadmium stress on oilseed rape (Brassica napus L.) in cadmium-contaminated soil","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-09-25 18:45:30","doi":"10.21203/rs.3.rs-4976345/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"e1b95f6e-a8f8-4df6-a8f1-a65365dbd166","owner":[],"postedDate":"September 25th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-01-02T22:08:09+00:00","versionOfRecord":[],"versionCreatedAt":"2024-09-25 18:45:30","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4976345","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4976345","identity":"rs-4976345","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}